Author: admin

    Rockhounding and Gemology

    Posted on by admin

    Rockhounding and Gemology

    by Mark

    Rockhounding helps gemologists and mineralogists hunt and discover minerals and precious gemstones like jasper, opal, agate, turquoise, geodes, zircon, black spinel, garnet, varieties of quartz, topaz and tourmaline and so on. People can choose either popular sites for rockhounding which normally have the ease of accessibility or can hunt and dig and then choose rare sites where there is possibility of getting better samples as they would not have been visited by all rockhounders. Fossicking is another technical term used to refer to the process of searching for gemstones and rockhounding which is used when looking for fossils, mineral specimens etc.

    Rockhounding and Gemology

    Rockhounding helps gemologists and mineralogists hunt and discover minerals and precious gemstones like jasper, opal, agate, turquoise, geodes, zircon, black spinel, garnet, varieties of quartz, topaz and tourmaline and so on. People can choose either popular sites for rockhounding which normally have the ease of accessibility or can hunt and dig and then choose rare sites where there is possibility of getting better samples as they would not have been visited by all rockhounders. ‘Fossicking’ is another technical term used to refer to the process of searching for gemstones and rockhounding which is used when looking for fossils, mineral specimens etc.

    Rockhounding in the early days was done mainly for getting valuable minerals and gemstones that are later used for commercial purposes. But the popularity of rockhounding grew with time, and today many rockhounders do it even as a hobby and collect beautiful gemstones and minerals for recreational purposes.

    Rockhounding and Gem Sources:

        • RockhoundingGem and Mineral Clubs:

    The gem and mineral clubs resent in the area chosen for rockhounding or in the area of residence of rockhounders provide useful information on rockhounding sites based on people’s interest and preference of gems. They also organize group trips to rockhounding sites which help rockhounders share and learn more information from experienced rockhounders.

        • Gem and Mineral Shows:

    The gem and mineral shows in the rockhounders’ area act as excellent sources of published information for finding good gem and mineral clubs.

    Tools Needed for Gems Rockhounding:

        Rockhounders who begin rockhounding as a hobby but do it consistently may go on to become avid collectors and would learn in the process to identify and classify gems. This process may later lead them to undertake and learn mineral and gemstone cutting and mounting. For carrying out the process of gemstone cutting and mounting, the equipments needed are rock saws and polishers. Rare and beautiful gems and crystals are generally found in very small samples. So for collecting and studying about this a good microscope is essential for rockhounding which would help rockhounders work efficiently with the specimens.

      • Knowledge Gathering:

    It is also vital to know the rules and regulations of the rockhounding site while hunting for gems. For instance, California state parks do not allow collecting of gems during rockhounding in these areas.

      • Protection:

    Rockhounding for gems is not generally a dangerous activity. However, there are a few safety issues to keep in mind. During rockhounding for gems, people should be mindful of the elements or hazards and how to protect themselves. Some of the common elements rockhounders must take care of while rockhounding for gems are:

        • Weather:

    It is essential that rockhounders study about the weather and wear clothes that best suit the weather. Rockhounders while hunting for gems during daytime can wear hats and sunscreen to protect against excessive exposure to the sun.

        • Mobile Phone and Emergencies:

    Proper steps and care must be taken to carry mobile phones and inform related people while rockhounding sites are out of town. Some areas are 4WD access only so if you have doubts, please check the suitability of the road for your vehicle before setting off.

        • Physical Fitness:

    It is very important for rockhounders to take much care of their physical fitness while rockhounding for gemstones. Proper care must be taken to avoid dehydration during very hot weather. Rockhounding for gemstones being a physical activity, it is vital that rockhounders take regular rest breaks as and when required and must check their own level of physical fitness at consistent intervals.

        • Weather Conditions and Safety:

    Most gemstones are found near water sources and so rockhounders must take care if they are not swimmers.

        • Wildlife and Poisonous Bites:

    Rockhounding for gemstones near or inside bushes have possibilities of venomous snakes or spiders. Rockhounders must take a first aid treatment bag in hand to handle such situations. Rockhounders must also generally avoid taking pets with them while rockhounding for gemstones as in many areas, pets are not allowed.

        • Site Safety:

    It is essential that rockhounders, after hunting for gemstones, must take proper steps to fill the environment back in original shape. That is, rockhounders must backfill all holes and must not tunnel into banks. This is because unfilled holes and unstable banks are potentially dangerous and could cause environmental damage. So rockhounders must take proper steps to maintain the environment and provide a friendly environment for other rockhounders. Also, some rock sites for gemstone hunting could be slippery and so rockhounders must take essential steps to handle unstable footing.

        • Traffic and Road Safety:

    If the sites for rockhounding gemstones are adjacent to roads, then rockhounders must be careful not to hinder or obstruct vehicles in the area.

        • Fire Safety:

    All fire regulations and restrictions must be followed by rockhounders and campfires must not be lighted if the rockhounding sites do not have permission to do the same.

    Rockhounding for gemstones help gemologists in various ways and rockhounders must take responsibility for maintaining the environment. This would help the rockhounding process to be handled by rockhounders efficiently and pave the way for the discovery of many more rare and precious gemstones.

    Each gem has separate methods and activities to be followed for rockhounding. For instance, rockhounding for sapphires would need rockhounders to wear old clothes for the activity as it can get muddy and dirty. Also, sapphire rockhounding sites would generally be located in areas some distance from the town and so rockhounders hunting for sapphire need to carry plenty of water and wear sunscreen or a hat. Zircon is another gemstone many prefer for rockhounding which is associated with sapphire and is available in most areas in variety of colors ranging from clear, light yellow, and a deep honey brown to the orange and red spectrum. Black spinel is one other gem that is usually found with the sapphire. An opaque black mineral, the black spinel works well as a cut gem.

    Rockhounding in California

    Posted on by admin

    Rockhounding in California

    by Ritika

    California is abundant with geological forces where mineralogists and gemologists can rockhound for the largest variety of rocks and minerals. The rock and mineral wealth of California has made California the most interesting and one of the oft visited places for rockhounders.

    California is abundant with geological forces where mineralogists and gemologists can rockhound for the largest variety of rocks and minerals. The rock and mineral wealth of California has made California the most interesting and one of the oft visited places for rockhounders.

    Desert of California Visited by Various Rockhounders

    RockhounderThe place is visited by all types of rockhounders like rockhounders hunting for rare and precious minerals which are used for commercial purposes as well as rockhounders who rockhound as a hobby and for hunting beautiful rocks and minerals. In earlier days that are before 1930 the desert of California was visited for rockhounding for commercial interests. However, after 1930 the interest for rockhounding increased among people that resulted in the formation of rockhounding groups and rockhounders began to make group visits to the desert of California even for recreational purposes.

    The Reason for Rules and Regulations while Rockhounding in Desert of California

    In earlier days there were no government laws laid on the rockhounding areas of the desert of California. However, as the rockhounders’ visits to the desert of California for rockhounding increased, it resulted in substantial amounts of rocks and minerals being removed by certain people alone. This action of rockhounders compelled the government of California by 1960 to lay rules and regulations for rockhounding activities in the desert of California.

    Source of Information for Rockhounding in Desert of California

    There are various places where rockhounders can carry out their rockhounding activities in the desert of California as per their preferences of rocks and minerals. For knowing more about the places for rockhounding in the desert of California there are various sources and methods. Some of the vital ones among these are:

    • Groups for Rocks, Gems, and Minerals: Rockhounders can join any of the gem, rock, and mineral groups present throughout southern California. Rockhounders can make initial studies about the rock, gem, and mineral groups before joining and join the groups that match their interest in gems, rocks or minerals. Via this rockhounders can get rockhounding advice from experienced rockhounders and these communities also arrange group visits to various places in the desert of California.
    • Libraries and Bookstores: Rockhounders can gather abundant amount of knowledge by visiting bookstores, libraries and “gem and mineral shows”. This would help them to gather various new sources of information and knowledge which they can use during their rockhounding in the desert of California.

    Rules and Regulation for Rockhounding in the Desert of California:

    Some of the vital rules and regulations laid by the government in the interest of the public and natural preservation which rockhounders need to follow while rockhounding in the desert of California are:

    • As stated the Code of Federal Regulations laid by the government of California, only reasonable quantities of rocks, minerals, semiprecious gemstones can be taken by a rockhounder as the source has to be available for all rockhounders without any disturbance.
    • In the above, the reasonable quantity as stated by field Office of California refers to not more than that can be easily held in a daypack by any rockhounder.
    • California government has also laid rules which do not allow rockhounding on developed recreation sites and areas.
    • Collection of petrified wood during rockhounding is allowed only if it is for non-commercial purposes and that also is allowed only from public lands with a limit of 25 pounds allowed for each rockhounder.
    • Rockhounders must get paleontological permit if they want to collect vertebrate fossils at the desert of California which otherwise would be considered as illegal and may result in a fine and imprisonment.
    • The collection of ovate bifaces, cores, flakes, and all other material worked by prehistoric cultures present in public lands is not allowed as stated by the Antiquities Act of 1906.
    • A separate publication named “Discovery, Location, Recordation, and Assessment Work for Mining Claims in California” gives useful guidance for mining claims while rockhounding in the desert of California.
    • Rockhounders can collect rocks for decorative rocks in reasonable quantity which means quantity that can be taken away in the trunk of any car is allowed for each rockhounder.

    So it is vital that rockhounders, before making their rockhounding trip to the desert of California must make essential study and gather information on whether the rockhounding site is open for collection.

    Vital Places for Rockhounding in the desert of California:

    There are various places for rockhounding in the desert of California for rockhounders as per their preferences for collecting minerals and precious gemstones. Some of the popular and most visited rockhounding sites in the desert of California are:

      • Amboy Crater National Natural Landmark (BLM Public Land):

    This place is best suited for rock collecting rockhounders. This is 250 feet high and 1,500 feet in diameter which is located in the Barstow-Bristol trough. This rockhounding site in California is a public land managed by the Bureau of Land Management.

    • Clipper Mountain Wilderness (BLM Public Land):

    This is a small cluster of volcanic mountains which covers a wide area from northeast to southwest.

    • Turtle Mountains Wilderness (BLM Public Land):

    This is the most visited place for quartz rockhounding which is technically termed as a best place for chalcedony and also for rockhounders who rockhound as a hobby.

    • Wiley’s Well Rockhounding District:

    Wiley’s Well Rockhounding District is located in the northeastern part of the Colorado Desert in southern California. This rockhounding site is the most popularly visited site by many rockhounders for rock-collecting. Here, some of the important rockhounding sites to mention are Hauser Geode Beds and Opal Hill Mine. Wiley’s Well District in the Colorado Desert at southern California is rich in jasper, agate, and geodes.

    The desert of California is the most visited place by rockhounders as it is abundant with minerals, rocks and rare and precious stones. Rockhounders must take care to travel in a group and also carry vital essential things in hand like drinking water while rockhounding. Some rockhounding sites require hiking and so proper care must be taken while rockhounding to these sites. All these steps will ensure that the rockhounding trip to desert of California is a remarkable and profitable one.

    Ruby Facts and Buying Guide

    Posted on by admin

    Ruby Facts and Buying Guide

    by Sheweta Dhanuka

    It is found in all shades of red however deep red colour is the preferred choice. The distribution of colour is mostly uneven that might be stripes or spots, supposed as pigeon’s blood, clear red with a trace of blue. The basic red colour mostly also comprises overtones of other colours.

    Ruby, the ‘lord of gems’ is one amongst the twelve precious stones God produced while creating life. Its name is derived from the Latin word ruber or rubrum that means red. It is the most valued gem hence in Sanskrit language, referred as ratnaraj that means “king of precious stones” and also ratnanayaka meaning “leader of precious stones.” It is the birthstone for those born in the month of July.

    Real rubies produced by Mother Nature are extremely rare and very expensive. Therefore, artificially red colored rubies are created by man made methods that are relatively quite cheap. Sometimes, few clever buyers sell these cheap stones at the price of the original gemstone. In order to avoid all future surprises buyers should ensure the credibility of the dealers. The seller must inform the buyers about the gemstone treatments and origin clearly. He/she should also give the certificate of authenticity along with the gem at the time of purchase to the buyer. This article is written with the intension to provide the gemstone lovers with all possible facts and information about the valuable red colored precious gem. This content would acquaint the buyers with the essential know-how about this remarkable gemstone.

    Colour – It is an extremely important characteristic. Being the member of mineral corundum (aluminum oxide) family, this exquisite gemstone owes its pure red colour to chromium element present in the chemical composition. Brightness and intensity of red colour increases with the increase of chromium. True and genuine gem possess intense saturated pure red colour with no tinge of either brown or blue. The glow of red colour is similar to that of burning coal. This amazing gemstone holds its beautiful colour in all light variations.

    It is found in all shades of red however deep red colour is the preferred choice. The distribution of colour is mostly uneven that might be stripes or spots, supposed as pigeon’s blood, clear red with a trace of blue. The basic red colour mostly also comprises overtones of other colours. Colour variations are different in each single stone that is no two stones have similar overtones. Few commonly seen overtones are red with yellowish to orange tones or blue to purple tones. All these colour variations complements the main colour and gives amiable look to the gemstone.

    Clarity – Second important characteristic is the transparency. It is the known fact that inclusions are always unwanted but with this gemstone it is different!! Certainly it is undesirable to have inclusions however these act as the certificate for the genuineness of the gem. All original rubies would consist of flaws. Chromium is liable for imperfections within the structure of the gemstone. The colour increases in direct proportion with the amount of chromium in the chemical composition and so is the clarity. The biggest difference lies; colour is positive trait while clarity becomes negative. Chromium results in large number of fractures and infinitesimal indiscretion inside the crystals. This is the reason why this marvelous gemstone always consists lots of defects. Ruby without any inclusion is miracle of the nature and thus it is priced as high as sky.

    Cut – Beauty of the stone lies in the hands of the cutter. The final look is dependent on the cut being given to the gem. With the perfect cut, the stone could appear bigger in size in spite of being less in weight. It is often offered mixed cut, that is by and large oval, but could be round or any other shape like square, rectangle etc. Ruby beads or cabochons are also extensively seen in the jewelry market.

    Carat Weight – It is found mostly in small sizes and less carat weight. Gemstones beyond 3 carat in weight are exceptionally rare and scarce in nature. This captivating gem is priced very high per carat and when it is more than 3 ctw then the price per carat weight gets doubled making it enormously pricey.

    Price – At present this entrancing gemstone fetches maximum price than all other gemstones even the price paid for diamonds. The reasons are many like rarity, scarcity and exceptional features etc. Overall it is the expensive gem and further the price is determined on the basis of origin, colour, clarity and carat weight. Stones from Myanmar are the most sought after and treated as luxury stones. Then comes Thailand and Sri Lanka followed by other parts of the world. Pure intense red colour, minimum flaws and high carat weight are the pinnacle points in terms of price determinant. Financial value of the gem increases with the increase in these points. Original gems possessing all the summit points at the auctions outdo every other thing.

    Few high quality gemstones exhibit unique phenomena of six-point star pattern, called asterism. It is caused due to fine rutilum needles present in structure along the crystal facets. When light is reflected from these needles the stones displays the star pattern. Such gems are over and over again fashioned into even cabochon cuts to best flaunt the phenomena. Further, when seen under a complimentary light source the star gives the impression of moving from one corner to the other corner of the stone with the change in the lighting angle. These gems are called as ‘Star Rubies’. It is rare in nature and very expensive. These gems must show varied rays and the star should be visible in the center of the stone. Price is determined in the order of – beauty, attractive colour and last the transparency.

    Source – Myanmar has been the prime source of preeminent ruby for many years. Mines at Mogok are the oldest mines for this gemstone. The special feature of strong fluorescence is exhibited when exposed to sunlight by the stones procured from this country. Slight pink reddish colored gems are also obtained from the renowned mines. Thailand is the second largest producer of fine quality gems consisting bright red colour. Few Thai gems produce phenomenon of extinction that is black reflections. Sri Lanka comes next in the list. Rubies acquired are fine-looking and habitually seizes pinkish or pastel tint.

    This red beauty is procured from many other parts of the world for example Afghanistan, Pakistan, Australia, Pamir Mountains of the Commonwealth of Independent States, few states of United States and Greenland. African and some more Asian countries also contribute some amount of this precious gem to the world gemstone market. Gemstones with minimum or negligible clarity are found in Karnataka and Orissa state of India.
    Enhancements – Enhancement is common for this divine gemstone. It is treated to enhance the colour and improve the clarity. Man-made dyes are used to augment the colour while surface fractures are hidden through coatings. An ordinary coating does not last for long. Thermal enhancement is considered constant and everlasting. Under this process, the chemical like sodium tetraborate powder is melted under very high temperature and coated on the surface of the stone. The liquid chemical enters the fractures and covers it up. After sometime, the chemical solidifies as an amorphous solid and hides all the flaws. The international gem and jeweler trade acknowledges this treatment.

    Imitations – Gemstone markets are flooded with imitations of this pretty gem. The synthetic stones look exactly identical to the original stones that it is almost impossible to spot the real gemstone. However one very simple tip is, natural rubies possess imperfections within it while the fake stones are created as perfect stones without any defects. Apart from this tip, either gemological testing or truthfulness of the seller could depict the originality of the gemstone. Black Ruby, Timur Ruby and many more such trade names are the faulty names created by the swindle dealers to mislead the buyers with poor quality red spinels or garnets at the high price of original rubies. Therefore, buyers should confirm about the reputation and reliability of the gemstone dealer. Only after 100% satisfaction the final purchase should be made in order to avoid upcoming bombshells.

    Use – This fabulous gem is widely used for making charismatic jewelries in every corner of the globe. All the ornaments holding ruby are made with 14K or 18K yellow gold, white gold and platinum. Sterling silver can also be used but for such classy high priced gemstone it is seldom used moreover, it is not advisable. The stone used is less than three carat in weight. It is very well paired with diamonds to create breath taking rings, pendent, earrings and bracelets. In pairing, ruby is large in size or in the leading position while diamonds are placed in a way to emphasize the beauty of main stone.

    Today, the jewelry designers’ craft attractive earrings variety like stud earrings, hoop earrings and drop earrings. Stud earrings comprise of single large size stone to give royal look. Drop earrings embrace small stones less than two-carat weight as this variety offers sophisticated glance. Pendent and necklace are also available in eye-catching designs to harmonize the neck of the female. At present rings with ruby are embraced by females all over the world especially modern brides. Rings with ornately hued rubies along with diamonds in platinum or white gold are the prime liking for the wedding, anniversary and engagement rings as it articulates a woman’s only one of its kind persona.

    After rings it is bracelets in the selection to complement the delicacy of women’s wrist. Same as rings it also includes unrivaled pairing of this gorgeous gem with diamonds. At the time of purchase the buyers should look for the right width of the bracelet. The gap between the bracelet and wrist must ideally be one finger width. It should not be too long else it would seize the attire and lay strain on the hinge joints and if too short then it would be uncomfortable and injure links and joints.

    Precautions – It is red variety of the corundum mineral; one of the hardest minerals found on the earth crust therefore, it is tough and durable gemstone. It rates 9 Mohs on the scale of mineral hardness. The hardness rate specifies that this astonishing gemstone is ideal for daily wear jewelry and can easily withstand all the odds like sudden temperature changes, ultrasonic home cleaner and so on. Unquestionably it is a sturdy gemstone but at the same time it is a valuable asset for the lifetime. It would be treasure in the time to come therefore all general gemstone precautions and care should be put into practice. The jewelries holding this beautiful gem must be protected from hard blows and hits. In order to sustain the natural glow of the stone avoid wearing it while working with household cleaning agents and harsh chemicals etc. Most important, always protect your ruby or its jewelry from theft and damage. With these small steps one could retain the priceless gemstone longer than the expected lifetime.

    Beliefs – Red colour of this splendid stone symbolizes ardent and rampant love between two people. It is also associated with fire and blood that refers to warmness and liveliness in life. It is believed to stave off bad dreams when kept under the pillow. It should be worn in left hand to boost its power of protection. It helps the wearer in finding true friendship and love. It also lends a hand to the wearer in overcoming negative traits such as apprehension, depression and anxiety. It proffers confidence and zeal towards life and assists in attaining opulence and authority.
    As it is allied with blood it is thought to enhance the blood circulations and heal the pain from related illness. It abets in purification of blood through sanitization and removal of infection or germs. It is even believed to reinforce neurological tissues around the heart. Astrologers recommend politicians and people involved in administrative work to wear this gem in left hand. Females who have miscarriages are suggested to wear this extraordinary gemstone ring to avoid such unfortunate misshapenness in future. All these effects could be experienced only when the wearer wears the original ruby. The ideal weight and size of the stone varies from person to person. It is determined on the basis of height and weight of the wearer.

    Red colour of this fascinating gemstone symbolizes love, warmth and passion. It truly deserves to be well thought-out as king of gemstone as it acquires all it takes for the same such as influential appearance, radiant colour, outstanding hardness and an irresistible brilliance. Hence to own the king, be prepared to spend like a king!!!!

    Ruby Facts

    Chemical CompositionAluminum oxide with chromium and the chemical formula is Al2O3,Cr.
    ColoursAll shades of red with hue of blue, brown, yellow and orange.
    Hardness9.0 Mohs
    Refractive Index1.762-1.778
    Specific Gravity3.96 to 4.01
    LusterVitreous
    Solid StateTransparent to Opaque
    Crystal SystemTrigonal
    Dispersion0.018
    CleavageNone
    FracturesUneven or conchoidal
    PleochroismStrong
    EnhancementMostly enhanced
    SourceMyanmar, Thailand, Sri Lanka, Afghanistan, Pakistan, Australia, USA, India, Nepal and other African countries.
    PrecautionsAll general gemstone precautions and care.

    Equipment needed for Rockhounding

    Posted on by admin

    Equipment needed for Rockhounding

    by Ritika

    Rockhounding is a term used for the activity of rock hunting or collecting rocks and mineral samples from nature. This is more as recreation and hobby oriented and not from the commercial point of view. It has humble beginning as many die-hard rockhounders will tell you. Walking along they chanced upon a beautiful stone, which led them to look for more and more and suddenly they were avid hunters.

    What is rockhounding?

    Rockhounding is a term used for the activity of rock hunting or collecting rocks and mineral samples from nature. This is more as recreation and hobby oriented and not from the commercial point of view. It has humble beginning as many die-hard rockhounders will tell you. Walking along they chanced upon a beautiful stone, which led them to look for more and more and suddenly they were avid hunters.

    In the early days, rock hounds were generally those who were prospecting gemstones and minerals for commercial use. Soon people were attracted to this as a hobby simply because the natural beauty of the stones and the adventure involved was so varied and interesting that they left the commercial aspect to the commercial dealers.

    Rock hounding is all about looking for interesting pieces of gemstones, minerals, or even just stones that nature created. There is no point in talking verse and prose about gemstones if you cannot recognize what you have in your hand. The finished product is what we see in the shops but out there in the rough they look very different. So it is important to learn how to recognize a potential rock for gemstones.

    There are many places which have free sites for prospective rock hounders. Then there are paid sites too. These are usually places where gemstones and minerals have been found regularly. There are maps available but a first timer would do well to visit known and established digs initially. Of course, your best bet is to join the local rock hounders group where you will meet experienced hunters who will have many a handy tip for you. Clubs organize field trips to educate you in the art of rock hounding and along with new friends you get to learn all there is to know about rock hounding.

    Today there are many clubs and groups that support this hobby. There are books on the subject and you can get lots of information at your local tourist centre, the chamber of commerce and of course, the ever present internet. Some states have laws that regulate rock hounding on public land and most national parks prohibit this activity so read up on local laws governing rock hounding activities.

    Getting Started

    Rockhounders need nothing more than a rock hammer to start off. This is a small but precise tool which has a flat hammer on one end and a pick look-alike point at the other. The hammer end is to break up the rock and the pick is used to dig in to crevices to root out the mineral or gemstone. Rock hounding is very interesting. A keen collector will become well conversant with petrology, geology and mineralogy while hunting for rocks. It is important to learn about classification and identification of specimens so you are aware of what you have collected. Many times this hobby has led people in to the business of lapidary, mounting and cutting of gemstones and minerals on a decent sized scale. Here your equipment requirement changes a bit as now you would need polishers and rock saws, a good microscope to enable you to work with crystal varieties etc.

    Safety and Equipment Requirements

    Safety First

    Safety is of paramount importance when rock hounding. Your area of operation would cover most remote and far off locations in dirt, sand and rocky terrains where help is not easily available. You must be as prepared as is humanly possible to cover all eventualities and situations.

    There are some key safety features you need to keep in mind:

    • Travel in groups
    • Carry lots of drinking water and
    • Ensure that you have plenty of fuel to bring you back.
    • If you are a lone ranger, then ensure that people know your plans.
    Equipment

    Rockhounding EquipmentsLet’s start with safety goggles because breaking rocks down means bits of rock and tiny microscopic particles are going to fly. Eye protection is hence of utmost importance. Next is the resultant dust and dirt which you can breathe in so a respirator or a protective mask is your second most important requirement.

    Other than the above two, experience has taught people not to leave home without the following items packed in your rock hounding kit.  (image courtesy: http://www.gemworld.com/GeologyTools.asp)

    • A First Aid Kit is essential as bites, scrapes, cuts and bruises are part and parcel of rock hounding.
    • Maps and guide books to tell you were to go and how to get there.
    • Spare tire and your tool kit, rocks and tires don’t go well together.
    • Garbage bags to carry all your trash and they can be used to wrap up large samples too
    • You need a magnifying glass small enough to hang around your neck so you don’t miss out on the smaller finds.
    • A notebook and writing tools like pencils pens etc to take notes on what you have collected.
    • You need a good quality rock hammer which is made of steel so the head does not snap off. Sheath them so they last longer and paint them a nice bright color so you can spot them easily.
    • Chisels, garden trowels and a round point shovel and hoe set will help you dig around.
    • Containers of assorted sized to collect and store you samples as you go along. You could try egg cartons, milk crates, sacks made of canvas, cardboard cartons, cookie tins and whatever else you deem fit.
    • Medication other than the first aid kit, sunscreen and hats, lots of food and snacks, toilet paper, camping gear and last but not the least
    • Loads of patience and common sense and presence of mind. Most people tend to forget the last three but these are the most important and you cannot do without them.

    Rock hounding is a fun and enjoyable activity if you don’t let yourself get carried away with it. Patience is the key as is perseverance and you are sure to strike gold some day.

    World Famous Rubies

    Posted on by admin

    World Famous Rubies

    by Yuman Hussain

    There are some amazing rubies which are world famous for their beauty, color, cut and clarity. A stone renowned for passion and power it has been remained favorite with royalty and dynasties since antiquity. The beauty of this stone had been extolled in several books, travelogues and memoirs of travelers, poets and writers.

    Summary: There are some amazing rubies which are world famous for their beauty, color, cut and clarity. A stone renowned for passion and power it has been remained favorite with royalty and dynasties since antiquity. The beauty of this stone had been extolled in several books, travelogues and memoirs of travelers, poets and writers.Ruby

    Do you know that rubies are most sought after jewel right from antiquity? The royalty and wealthy classes had exquisite collection of rubies. There are many references to these magnificent stones in Bible and ancient Indian Sanskrit texts. The rarity and red brilliant color with fiery flashes have attracted passion and love .It was the symbol of power for the mighty rulers. Burma has continued to be famous for producing world class rubies since antiquity. In ancient and medieval period the Mogok mines were controlled by Burmese kings therefore all stones were part of royal treasury. A giant ruby of 77 ct was discovered by Burma Ruby Mines Ltd in 1899.King Mindon Min sold one stone weighing more than 36 ct to western traders in exchange of cash. However not much is known about the existence of these stones except mention in the literature.

    During the reign of King Thebaw in 1878- 1885 a beautiful stone weighing 100 ct was discovered at Mogok an area famous for many magnificent rubies. This stone was presented to the King by the governor of the ruby mining district as a mark of respect. King Thebaw believed to have stunning Burmese rubies collection. There can be no doubt that all large stones were the property of the state. Jean Baptiste Tavernier a 17th century traveler had written extensively about some of the largest rubies in his famous book ‘Travels’. However in those times every red stone was considered ruby. So it is likely that some of these stones could be spinel. It is interesting to know about some of the exceptional rubies who guided the fate of rulers and dynasties world over.

    Stunning Star Rubies
    Rosser Reeves Star Ruby

    Rosser Reeves Star Ruby

    It is a finest and largest 138.7 carat star ruby placed at Smithsonian Institution Washington D.C. This brilliant stone was found at Sri Lankan mines. Named after Mr Rosser Reeves who donated it this stone is clear almost translucent with six rayed star. In 1966 it was insured for $150,000.

    De Long star Ruby

    Delong Star Ruby

    It is a 100 carat oval cabochon displayed at American Museum of Natural History New York. Martin Ehrmann sold this piece of beauty to Edith Haggin De Long for $21,400.

    Brilliant Burmese Rubies
    Edwards Ruby

    Named after Major General Sir Herbert Benjamin it was 167 carat Burmese ruby donated by John Ruskin in 1887 to British Museum of Natural History.

    Peace Ruby

    A 25 carat (43carat uncut) brilliant stone was found at the end of World War I hence the name. This magnificent ruby was mined in 1919 from Mogok mines. It had an irregular hexagonal shape with a flat apex. The color was amazing perfect red as deep as pigeon’s blood. A beautiful stone with unblemished clarity it was purchased by Indian trader in Burma and cut in Bombay into exquisite flawless appearance. This stone was bought and sold several times over the years. However present location of this stone is unknown.

    Anne of Brittany Ruby

    A beautiful but irregular 105 carat stone is displayed at Louvre Paris.

    Maung Lin Ruby

    It was one of the greatest Burmese Rubies discovered in Momeit in King Mindon Min’s rule in 1853-78. A stunning 400 carat stone was unsurpassed in beauty. The historical records say that the owner of the stone broke the stone into two gifting one to the King Mindon Min and sent the other half secretly to Calcutta. When King came to know about it he ordered its return. The second stone was purchased at an enormous price and returned to Burma. These stones were again recut with one stone with 98 ct named Nga Mauk and the other stone weighed 74 ct came to be known as Kallahpyan. These were taken to England when British annexed Upper Burma.

    Alan Caplan’s Ruby or the Mogok Ruby

    Mogok Ruby

    It is really impossible to find out about the finest ruby ever present. However this stone holds the distinction of being finest with a highest per carat price. It is 15.97ct untreated Burma beauty auctioned by Sotheby in 1986 .It was reportedly purchased by Graff and later sold for a whopping sum to Sultan of Brunei.

    J.N Forster Rubies

    The two most important Burmese rubies in Europe were a red cushion shape weighing 37 ct and drop shaped 47 ct stones. James N. Forster of London later recut these stones into somewhat smaller pieces. These stones traveled from Burma to England under tight military security and it is widely believed that Burmese King under duress allowed there shipment.

    Nga Boh (‘Dragon Lord’) Ruby

    It is a 44 ct uncut ruby found at Bawbadan, and 20 ct, when cut. It was one of the finest of its size ever found .It was presented to King Tharawadi. This stone went missing during British conquest of King Thebaw’s palace.

    Chhatrapati Manik Ruby

    A magnificent Burmese oval cabocarbon with deep red color, this stone has an oldest history dating back to almost 2000 years to the reign of Vikramaditya King of Ujjain. He proclaimed himself as Chatrapati a ‘Supreme King’ and upon advise of his astrologers put the stone in the centre of his crown.

    A representation of the gem said to be the Chhatrapati Manik Ruby. At left is a view of the gem mounted in a diamond tiara.This magnificent ruby then was passed to Traders and other rulers from the descendents of the King Vikramaditya. The ruler of Golconda Tara Shah loved the stone so much that he engraved his name on it and ordered a book of poetry to be written extolling its virtues. Later when Mogul Emperor Aurangzeb defeated Tana Shah he ordered to remove his name and put his name instead. Aurangzeb later presented this stone to the bankers of Murshidabad in recognition of their services to Mughal Empire. Later this stone was sold in England and mounted on a diamond tiara.

    Hixon Ruby

    Another fine Mogok ruby crystal it is displayed at Los Angeles County Museum of Natural History. Weighing almost 196.1 ct it has flawless surface.

    One of the largest rubies was discovered at Thailand. A giant brilliant 150 ct stone was publicly displayed during gem fairs.

    Rough Rubies

    Several brilliant pieces of ruby stones are displayed in some of the world’s leading museums. The British Museum has on display a hexagonal prism of 10×7″ weighing 34lb from North Carolina. Another specimen is 12x9x4 cm weighing 105 lb. It is a single crystal piece.

    Rubies have continued to hold fascination of the people. A rare stone it is amazing to know about some of the brilliant pieces which have emerged in the history of mankind generating feelings such as passion, love, envy, greed and love. Ruby will remain have special place of honor among the lovers of finest jewelry and gemstones.

    Ruby types

    Posted on by admin

    Ruby types

    by Madubanti Rudra

    Going to buy rubies? Read on the article below to learn about the classifications of this outstanding jewel to make an informed decision.

    Are you in search of a unique gift to impress your Valentine? Or are you a person into many years of marriage who wants to add some spice to his love life? Are you looking for some unusual way for expressing love to the special person in your life? Whatever may be the case, say, “I love you” with a ruby and see the sparks fly instantly. This is a gem, which has often been equated with human passion of the highest level. What could be more expressive than letting a part of your thought be known through this remarkable gem? So if you want to share the warmth of your heart with the person you love or you wish to express your passion, make a ruby the conduit of your emotions. Since antiquity, this red member of the corundum family has been adored by Royals, as well as commoners for its blood red hues and flaming radiance. The original grade one rubies, which are rare to the point of extinction, often out price diamond of similar size.

    If you want to learn about the types of rubies, you have to first understand the chemical composition of this magnificent stone. Rubies originate from the ore of Aluminum oxide or corundum. The hardness of ruby is measured 9 on Mohs scale and its specific gravity is 3.96 – 4.01. Its glow is due to its refractive index, which is 1.759 – 1.767 to 1.770 – 1.779. These qualities make the rubies especially suitable for jewellery making.

    We borrow the name of ruby whenever we try to describe anything red. But you can find many variations in shades of red in this July birthstone. These variations are the result of the presence of inclusions in the stone. While the chromic oxide is responsible for the red hues, ferric oxide lends it yellowish tints. Intense reds in certain rubies are the function of titanium. You can even find rubies with pink, purple, orange and brown shades as a result of the presence of chromium and iron in varied degrees.

    Apart from the color, it is the places of origin that accounts for the broader classification of rubies. If you are a gemstone enthusiast, you might know about the value of Burma rubies. Even if you are not, it is likely you might have heard about them. These are the rubies with the greatest fame and in optimum demand. Its fame stretches long back to the days of Marco Polo who has made a mention of these precious stones in his travel accounts.

    You will find that the rubies mined in Thailand finish a close second in the race for the top position. However, more or less the same quality of rubies can also be found in the countries like Vietnam, Sri Lanka, Afghanistan and Africa. They are similar in the sense, that they possess similar chemical as well as physical properties. Then how are they distinguished from each other? It is their unique shades that make them distinguishable according to their places of origin. Let us examine the discernible qualities of some of the world famous varieties of rubies.

    Burmese rubies

    Burma has been the source of the world’s most superior quality rubies. It is the fierce red displayed under any kind of light that makes these Burmese rubies one of the most coveted jewels in the world. The unique color in Burmese rubies is described as ‘pigeon’s blood’. The chromium impurities are accountable for this flaming red in Burmese rubies. The regions around Mogok in northern Burma and Mong-Hsu to the east of Mandalay are famous for ruby mining. Kinds of blemishes are the essential attributes of any natural stone. Burmese rubies contain the least of them. Sometimes they do come with inclusions in blue or pink shades.

    Thai rubies

    Next in order of quality, Thai rubies come second. Thai rubies come with rather darker undertones caused by the presence of iron along with chromium. Thus you find the Thai rubies with brownish to burgundy hues. Also known as Siam rubies, these of course are no match for their Burmese cousins. Most of them are heat-treated. Chantaburi and Trat provinces lying in the south-east of Bangkok are famous for ruby mining.

    Sri-Lankan rubies

    If you want a match for those gorgeous Burmese rubies you can some times find it in the Sri-Lankan rubies. These rubies with pink tints have a unique beauty of their own.

    Vietnam rubies

    Vietnamese rubies have a standard as high as Burmese rubies. Yen Bai and Nghe are two of the prime mines of Vietnam. They have an unpredictable supply.

    Tanzania Rubies

    In Tanzania, ruby deposits are found in regions near Songea. The color of these rubies resembles the garnet so closely that even jewelers are often baffled by their closeness. It has been noticed that the intensity of color diminishes with size. Therefore, the smaller the Tanzanian rubies are, the more they command price.

    Madagascar rubies

    Two regions in Madagascar; Andilamena and Vatomandry are recent additions in the world ruby mining map. Here ruby occurs in a large number of igneous rocks. Apply a little bit heat treatment and wow! They are almost equal to their Burmese cousins in beauty and vitality. They are special from the aspects of gemological and mineralogical properties too.

    madagascar rubyThe deposit discovered in the Andilamena region is quite substantial and has been much into production of rubies in recent years. The rubies mined in the Vatomandry region do not require heat treatment. The rubies mined here are found in attractive crystal forms in shades of orange, red and pink.

    Afghanistan rubies

    Little is known about ruby mining in Afghanistan. However we find its reference in the writings of travelers as early as 951 A.D. Ibn Batuta, Al Biruni and Marco Polo discussed about ruby mining in Afghanistan in their travelogues. Balas ruby mines of Badakshan and Jagdalek appear to be authentic sources of rubies in Afghanistan. Not much is known about the gemological properties of Badakshan rubies. However the physical and chemical properties of Jagdalek rubies account for ruby crystals in faint colors to deep red. Often they are slightly purplish and strongly fluorescent. Occasionally violet rubies have been mined in these desolate mining regions. Afghanistan rubyAfghanistan Ruby image courtesy: mineral.galleries.com

    Synthetic rubies

    Synthetic rubies are primarily of three types- doublets, Verneuil or flame fusion and flux grown.

    Doublets:
    This type of synthetic rubies are not much in vogue nowadays. However they make great gifts. Doublets are usually stones of imitation backing with a natural corundum crown, generally made out of green or white corundum. When viewed carefully the joint made with glue can be noticed.

    Verneiul or flame fusion:
    The name is attributed to the process of production. They are easily distinguishable from natural rubies. These synthetic rubies are typically characterized by certain curved color banding known as striae. You can also find inclusions in the form of gas bubbles in them.

    Flux grown:
    This is the synthetic variety that you can not easily distinguish from a real one. Molten flux is crystallized under specified conditions of temperature and pressure to produce these versions of synthetic rubies. The stones might develop fractures when the pressure is released. Different processes of flux-grown rubies produce different types of inclusions. Often inclusions resemble that of natural rubies.

    Do you want to see the smiling face of your beloved? Then present her a gorgeous ruby and eternalize your love. The types of ruby described above will guide you through your purchase.

    Star Ruby

    Posted on by admin

    Star Ruby

    by Nasrina Parvin Khan

    Star Ruby is a type of rubies, which shows the special optical phenomenon “asterism”. “Asterism” is a phenomenon by which a star shaped light effect has been shown across the surface of the gem through the reflection or transmission of light.

    ‘Red’ is the color of passion, love, brightness and power. Every women as well as men are fascinated with this color .If we get a gem with color ‘red’ it will be a pleasing experience for us. It will fulfill our desire to get a gemstone with red.

    Is there any gemstone in ‘red’? Yes, it is “ruby”. Ruby is the most passionate as well as most precious gemstone in this Earth. The most important characteristic of this gem is its amazing color.

    The name ruby was came from the Latin word ‘rubens’ which means red. This excellent colored gemstone is considered as the King of Gemstone.

    India was considered as the classical country of rubies for a long time. In the Sanskrit (on of the classical languages of India) ruby is called ‘ratnaraj’ which translates as “King of the Gemstones”.

    Other important characteristics of ruby are its excellent hardness and brightness. On the Moh’s scale this splendid stone shows a hardness of 9, just after the diamond, the gravity is also high of this gem. It is 3.97- 4.05.

    Star RubyRarity is another important thing about ruby. Ruby is an extremely rare gemstone. Especially finer quality ruby is very rare.

    Ruby is the red variety of the corundum mineral. Actually the pure corundum has no color. Inclusions of little bit of other elements like, chrome, iron, titanium or vanadium are responsible for creating the color ‘red’. The ingredients of ruby are Aluminium oxide (Al2O3) and chrome with smallest proportions of other trace elements. But all the things are depends on the respective occurrence. Actually chrome is the element, which awarding ruby it’s amazing color deep inside the core of Earth, since the creation of the gemstone.

    Ruby occurs in metamorphic rocks, diplomatic marble and gneiss. Usually corundum mined from secondary alluvial deposits. Very rarely, it is mined from primary deposits.

    There are various kinds of rubies. But the most rare, valuable and attractive form of rubies is Star Ruby.

    WHAT IS STAR RUBY?

    STAR ruby is a rare variety of rubies. Nearly 3 stars are discovered in every 100 faceted corundum mined. Fine stars are more rare.

    Star Ruby is a type of rubies, which shows the special optical phenomenon “asterism“.

    “Asterism” is a phenomenon by which a star shaped light effect has been shown across the surface of the gem through the reflection or transmission of light.

    Star Ruby is one of the most popular star gems, which shows an illuminated, wavy star bellow the surface of the crystal.

    Usually Star Ruby shows the six legged star effect. But it can shows four to twelve rays depending on the crystal system of the gems. Twelve rays star effect in ruby is very occasional.

    WHAT CAUSES STAR EFFECT

    Star effect or “asterism” is caused by the dense inclusions of tiny fibers of foreign particles in gems. Generally, these inclusions are the reason of the reflection of light and form a wavy star like formation, which moves around when the mineral is rotated. All the inclusions in the gem are form via exsolution.

    Solid crystal inclusions found within the corundum ruby. Some rubies leave holes or empty areas in the host, which filled with liquid, gas or solid. Reflection creates from fibers or fibrous cavity in the crystal.

    The inclusions must be long, very thin needle like which called as ‘rutile’. “Asterism” is produced when the light is concentrate into 3 rays that intersects at right angles to the direction of the needles. Thus we get a six-rayed star. Small needles of rutile sometimes called ‘silk’ are oriented inside the minerals in the direction of the crystal growth system. There is relationship between the gem’s growth and the number of rays produced by the reflected light.

    The arrangements of needles in a hexagonal pattern produced six-rayed ‘asterism’.

    Exsolved inclusions form a pattern in the host mineral to form a star. This pattern remains same in case of ruby. The rays of star should cross at the top of the ruby and must be distinct.

    QUALITY OF A STAR

    The sharpness and the size of the star in ruby depend on the quality and quantity of rutile needles. We get a better star in ruby when the rutile packed more densely. Longer needles also produce a better star than the tiny particles. When the quantities of needles are much more, ruby turned into a low translucent stone and lack ‘asterism’. It also harms the color of ruby.

    CUTTING OF A STAR RUBY

    Cutting is very important to exhibit the star effect in ruby. Proper cutting helps to extracts the beauty of the gem. To display the star effect in best way, a ruby must be cut as cabochon with the girdle, parallel to the needles. Medium to high cabochons need to be cut to get a perfect star in ruby. The domed must be round or oval shaped.

    COLOR OF STAR RUBY

    The color of ruby is red. But the Star Ruby usually is not red. The Star Ruby available in red/pink or pink/red. Star Ruby from Sri Lanka is purplish brown. Generally the pinks have the best stars. Star Ruby with color ‘red’ is very very rare and costly. Red ruby with a perfect star are quiet impossible to locate.

    COST OF STAR RUBY

    The cost of red Star Ruby can reach at $50,000 per carat. Generally, three-carat pinks Star ruby sell for about $2000+ per carat whereas reds begin at about $5000 per carat.

    The value of a Star Ruby influenced by the intensity and attractiveness of the body colors as well as the strength and sharpness of the star. All six legs of the star should be straight and prominent.

    OCCURRENCE OF STAR RUBY

    Finer qualities Star Rubies mainly come from Mogok of Myanmar and Sri Lanka. Mogok material is the most fascinating. In the other hand African and Thai corundum do not produce stars due to the lack of rutile in the host material.

    FAMOUS STAR RUBY

    Rosser reeves star ruby

    The most famous spectacular Star Ruby is over 138-carat Rosser Reeves Ruby, which can be seen at the Smithsonian. It was mined in Sri Lanka.
    More Resources
    Ruby mineral specimens
    Buy Star ruby at gemhut
    Burma Star Ruby

    Places and Resources for Rockhounding

    Posted on by admin

    Places and Resources for Rockhounding

    by Ritika

    Rock hounding as a hobby often starts in the most innocuous of ways. Generally it starts with you finding something on the ground and it turns out to be a gemstone or a very pretty example of a colored rock. Soon you get tempted to find another and another and if you hit a lucky patch you could get addicted to the activity. But a newcomer must keep in mind that every day is not a Sunday and after that first lucky hit there may be periods of lull where you get nothing. Don’t give up, take the time out to study and learn all about rocks, their recognition and identification.

    Resources you can use

    Rock hounding as a hobby often starts in the most innocuous of ways. Generally it starts with you finding something on the ground and it turns out to be a gemstone or a very pretty example of a colored rock. Soon you get tempted to find another and another and if you hit a lucky patch you could get addicted to the activity. But a newcomer must keep in mind that every day is not a Sunday and after that first lucky hit there may be periods of lull where you get nothing. Don’t give up, take the time out to study and learn all about rocks, their recognition and identification.

    Recognition of gemstones and mineral is a very important requirement. You could have all the facts of geology at your fingertips but if you cannot identify and recognize what is in front of you then all your knowledge is of not much use. You could then just walk by a very rich outcrop of rock and lose out on some interesting pieces. Stones in the rough are very different from the finished products that we see. Learning all the visual signs of rockhounding are a very important aspect of this hobby.

    RockhoundingGet your hands on all the resources which will teach you about gemstones and minerals and the thousand other varieties out there in the rocks. One of the most thorough resources you could find is the Audubon Society Field book which has lots of pictures of gemstones. Everyone has heard of jaspers and rubies, sapphires, agates and emeralds but have you heard about chabazite and orpiment? Surf the net and you will find lots of mineral stone and gem stone galleries which are happy to provide you with visual pictures of every possible rock and mineral documented by man. Try to look for stones in their original state rather than the polished version. Educate yourself on how they look so if you chance upon one you can recognize it.

    Museums are another good resource which will give you all the information you need on rocks, gemstones minerals. Here you may find samples in their original raw form and there will be information on where the sample was collected from. People host talk shows and interactive sessions where they recount their experiences and this is vital to your hobby as each rock hounders experience is worth its weight in gold. Wherever you go rockhounding, ensure that you visit the local museum, the local Rockhounding clubs, the tourist information centers and the shops for detailed information. Every place has different features of rocks. If you found garnets in Colorado’s, Ruby hills, remember that in Idaho, the garnet bearing rocks may not look the same due to geographical influences. It basically means you cannot use one place as a reference for another, each place has its own unique features and terrains.

    With the study of rocks, their recognition and identification, their features you need to look out for etc all under your belt you can now take the research out in to the wild. Out there in the open you will not see gemstones winking at you in the sun, what you will see are rocks and outcrops that have gemstones and minerals pieces big and small hidden inside them. You must be able to identify external signs on a rock that will tell you if this is a potential find or not.

    Places you could start with

    Across the world there are lots of places where you can start your hobby of rockhounding. Of course the best place would be your local state or areas in the regions nearby. Most places have paid sites for digging or even free sites which allow for prospecting. There are maps and guide available for sale but for newcomers it is advised that you start off with an established dig and then as you grow in experience you can venture out on your own.

    Join the local gem and rock clubs where you can interact with rock hounders who have been in this business for decades. They have all the tricks of the trade up their sleeve and they can give you important guidelines and handy hints. Most will have personal gemstone and mineral collections and tales to tell about each. Rock clubs also organize field trips and you can benefit a lot from these. Once your eyes are trained to spot a potential find and your brain knows what to look for, you will find that your rock hounding trips are very fruitful and enriching in experience and content.

    For more information

    On the internet you will find there are detailed sites for individual places giving you information on the best sites etc. There are specific books pertaining to specific regions which contain loads of details, for example, the book, Gem Trails of Southern California which has fantastic pictures and important details on the where, how and why of rock hounding. There are others in the series like Gem Trials of Northern California, Oregon, Nevada, Pennsylvania, Washington etc which are all excellent resources of information on rockhounding.

    There is a rockhound handbook that contains all you need to know about rockhounding. Besides information there are some logistic requirements like tools, equipment and other basic things. You can learn about the formation of rocks and minerals, the how and the why, learn about what you should look for, how to prepare for a successful trip, how to identify commonly seen gems and minerals, preparation and storing of specimens collected etc.

    Besides the US, there are books on prospective rock hunting in the rest of the world also. The list is exhaustive; the places plenty so if you are an avid traveler, adventurer and keen rockhounder then the possibilities are endless, the resources are at your fingertips and all you need to do is pack your kit, your enthusiasm and your sense of adventure and you are ready for some serious gemstone hunting.

    Ruby Identification

    Posted on by admin

    Ruby Identification

    by Erum Qureshi

    Step by step laboratory identification procedure for Rubies. “There are numerous tests conducted to identify true rubies. Various characteristics and traits are judged by a gemologist to authenticate and grade a ruby”

    Identification of Rubies

    There are numerous tests conducted to identify true rubies. Various characteristics and traits are judged by a gemologist to authenticate and grade a ruby.

    Color

    The first criteria a gemologist looks for in a stone purported to be a ruby is the color – a strong red color, and a stone belonging to the corundum species will be the first very basic factors, which will decide if the given stone is indeed a ruby and whether it ought to be subject to further examination and tests to prove beyond doubt that it is indeed a ruby. Tests for hardness, for measuring the specific gravity of the stone and the refraction of light are just some of them.

    Physical Properties of Rubies

    Species

    ruby

    Corundum as a mineral would be colorless if pure. However the presence of one or more metallic oxides present in the stone as impurities gives corundum its colors. All stones belonging to this species ranging in varying shades of red to a deep crimson are called rubies.

    Light red, pink or even violet corundum are usually called sapphires because if they were grouped as rubies they would be stones of an inferior quality. Hence, besides red, all other colors of corundum are properly termed as sapphires with color prefix.

    Corundum is found in many colors besides red (ruby) and blue (sapphire). Colorless, yellow, violet, green and even brown colors may be found. The name ruby literally means red (derived from the Latin word – ‘ruber’.) Rubies vary in shades from varieties of red to a deep crimson due to traces of chromic oxide (Cr2O3) in its crystal structure. The amount of chromic oxide (usually 1-3%) determines the depth of color in the stones and traces of iron in the ferric state gives them a brownish tinge. The ideal color for a ruby would be a strong traffic signal red.

    Hardness

    Although corundum is a hard mineral (rating 9 on the Mohs scale of hardness) care needs to be taken during testing as they are slightly brittle and if dropped on a hard surface or given a sharp blow, are prone to develop internal flaws or fractures.

    Step by step tests to determine Ruby’s authenticity

    Determination of Specific Gravity (SG)

    Each gemstone has its own specific gravity which is ratio of its weight to the same volume of water.

    Sri Lanka Ruby

    The specific gravity of purest corundum is around 3.98, this value, way beyond the range of commercially sold heavy liquids usually used to determine Specific gravity. Therefore a special solution called “Clerici” is used. This solution contains very soluble thallium salts: the ‘formate’ and the ‘malonate’. The Clerici solution at a specific gravity of 4.00 is dense enough to float corundum at room temperature. Thus, in spite of being hazardous and viscous as compared to other high density liquids, it is used to measure the specific gravity of Ruby and Sapphire.

    The Clerici solution is an aqueous solution and can be diluted with distilled water. Ruby when suspended in a beaker of Clerici solution has to be clean and dry and so do the tweezers and other apparatus used for the test. Care needs to taken that these are free from other organic solutions before immersing the gem in the solution.

    Natural ruby will have an SG approximating 3.99 although there is a variation for stones mined from different localities. Once the SG is confirmed to be that of corundum, the gemologist moves on to the next step.

    Determination of Refractive Index

    Light rays leaving one medium and entering another obliquely seem to bend a little at the place of contact. This is called refraction of light.

    During gem testing, measuring the refractive index or RI helps the gemologist observe the indices of refraction of light on a particular species of gemstone. Spot readings are taken for cabochon cut rubies; faceted stones are placed facedown on the glass of a Refractometer with a small amount of contact liquid and the reading is taken. The RI of ruby will be between 1.76 and 1.77.

    The refractive index can sometimes be a decisive factor for successfully eliminating a ruby look-alike like tourmaline which will have a much lower RI of 1.61 to 1.66.

    Double Refraction Test

    When a ray of light enters a crystal having a Trigonal system in directions other than the optic axis, it splits into two distinct rays. This is known as double refraction. The Ruby, being of the Trigonal crystal structure shows two indices of refraction in a polariscope. These are known as the ordinary ray and the extraordinary ray.

    This can be useful in identifying gemstones, the difference between the highest and lowest refractive index is known as birefringence. Ruby has a birefringence of – 0.008, with a negative sign because the ordinary ray is of greater value.

    Pleochroism Test

    Because the ruby is doubly refractive (it has two rays), each of these rays absorbs light differently and this has an effect on the stone’s color. When it is turned, it shows a slightly different shade of color and this effect is known as Dichroism.

    The ordinary ray in ruby showing a deep purplish red is the most attractive and desirable for this species.

    Determination of Absorption Spectra

    The absorption of colored stones is in well marked bands or finer dark lines which cross the otherwise continuous spectrum, obliterating certain colors or wavelengths when white light is transmitted through or reflected from the stone.

    The spectroscope is an instrument that determines the wavelength of the absorbed light. The wavelength is measured in nanometers (symbol nm) or angstrom symbol ?. The spectrum most common to Ruby is the chromium spectrum. It is characterized by general absorption in the deep violet, transmission in the blue, an absorption band in the green and transmission in the orange and red.

    Fluorescence Test

    The luminescence of rubies whose coloring agent is chromium is a strong crimson / orange light when subject to any kind of radiation (short-wave, long-wave or even blue light). When viewed through the Chelsea color filter, this fluorescent red is visible. It is this property that can be used to distinguish between garnets and rubies – garnets do not fluoresce.

    Microscopic Examination

    Without doubt the final and most determinative test to decide the authenticity of any gemstone is its examination under a microscope.

    Gemologists rely on their expertise and experience to spot the inclusions before taking the final call on the authenticity and grade of a gemstone. Inclusions (irregularities in the crystal structure and internal flaws) in ruby are straight angular growth lines following the crystal faces. Included are rutile needles or hematite plates called ‘silk’, which bring about a soft sheen in the stone.

    cats eye effect on ruby

    When such a stone is cut en cabochon these rutile needles or ‘silk’ brings about the rare cat’s eye effect or the very desirable asterism (a six rayed star that shimmers above the stone’s surface when it is moved). Rhombohedral twinning and boehmite needles are inclusions exclusive to natural corundum and have never been observed in flux grown synthetic corundums. Inclusions typical to synthetic ruby are curved growth lines (thin striae or bands), gas bubbles and dense clouds of extremely fine rutile silk in star stones. These clouds do not show the straight angular zoning patterns that natural stones show, they have curving bands instead.

    Besides the observing the color, there are an array of tests to identify a given stone as a ruby. These tests, conducted by trained gemologists under strict guidelines using highly sophisticated equipment will establish beyond doubt the identity of any given gemstone. As it is next to impossible for an untrained eye to distinguish between synthetic and natural stones, or even ruby or a look alike from a gem of another species, these methods are valuable tools that help in identifying gemstones and making a correct, informed decision about their purchase or use.