Introduction to Gemstones
The Emerald stone gets its name from the Latin term Smaragdus which means green. With the color of nature, they are said to instill a calm and peaceful persona in the wearer. The first knownemerald mines were in Egypt, where they were mined around 1300BC, in a location later known as ‘Cleopatra's Mines', which can be found today on either side of Mount Smaragdus. Only after the discovery of the New World, they were sent in larger quantities to Europe.
To the Egyptians, emerald was a symbol of fertility and life. The Aztecs named them quetzalitzli after the bird of paradise, and a symbol of a new season.
Emeralds are available in a number of shades of green, from dark, deep green to soft green, grass green and light green. The most valuable emeralds are a pure, vivid green with a saturated, pure hue without any traces of other shades.
Hardness - 7.5 - 8.0 on Mohs scale
Specific Gravity - 2.63 - 2.91
Emeralds are relatively durable gemstones. While they are mostly resilient to knocks, they can get chipped or scratched. The hardness protects the stone to a large extent from scratches but it may develop internal cracks if hit against hard surfaces or if exposed to extreme temperature.
In Emerald one may see inclusions that dealers like to call an internal “jardin,” or garden, because they resemble branches or plant roots. It is extremely rare to find a natural emerald without flaws. In the crystallization process, most emeralds take up small bits of other minerals, gas, liquid, and crystals and are seen as inclusions.
Almost all natural emeralds have some treatment applied to them so that their colour improves and visible imperfections are eliminated. The industry-accepted practice is to use a colourless oil to fill in any cracks and strengthen the emerald against accidental chipping or breaking. There are a number of processes used to alter the color, improve clarity, or increase the durability of gems.
Emeralds can be sourced in many countries, some of which include Colombia, Russia and Brazil, which is the world's largest supplier of emeralds. Most of the emeralds for sale originate in Colombia and Zambia.
Emerald is the birthstone for the month of May. It's also the gem gifted on the twentieth and thirty-fifth wedding anniversaries.
This gemstone gets its name from Latin ‘Rubens' meaning red. In Sanskrit, the ruby is named ‘Ratnaraj', meaning 'the king of precious stones'. Forcenturies, the ruby has been admired as one of the most valuable gemstones on Earth. Mined in Burma and Sri Lanka since 8th Century BC, ancient Hindu and Burmese miners believed that colourless or pale pink sapphires were rubies which wereyet to ripen. With their brilliant red hues, Rubies are often related to themes surrounding the essence and vibrancy of life. This is the only gemstone that rightly represents the passion of love.
Rubies are found in shades of red, from rich darkish red to pinkish red. The red hue is drawn from some traces of the mineral chromium.
Hardness - 9.0 on Mohs scale
Specific Gravity - 3.96 - 4.05
Rubies are extremely strong. They are as resilient as sapphires and only slightly less tough than diamonds. The rubies with a vibrant red colour with a hint of blue are considered the most precious stones. The warm and fiery nature of the red color is incomparable with other stones. This gemstone has excellent resistance, durability, shine, and rarity.
The phenomenon called Asterism occurs when Star Rubies contain intersecting needle-like inclusions that cause the appearance of a six-rayed 'star'-shaped pattern when viewed with one overhead light source. The presence of a star is one of the most remarkable phenomena encountered in the world of colored gemstones. This optical occurrence is quite rare, being only found in a very small percentage of the rubies mined around the world.
Nearly all rubies have flaws and finding one without imperfections is exceptionally rare. In general, the clarity characteristics include thin mineral inclusions called needles. When the mineral is futile and needles are present in intersecting groups, it is called silk. Rubies also contain small crystals, zones of color distribution, or inclusions that look like human fingerprints.
A standard practice in the jewellery industry is to heat rubies to improve their colour and strength. Rubies which are free of any treatments and high quality in terms of colour and clarity are extremely rare to find and expensively priced.
Rubies have been found all over the world, including in Myanmar (formerly Burma), Africa - Mozambique, Australia and the USA. The majority of rubies for sale at TT GEMS originate in Myanmar, Mozambique and other locations in Asia.
Originally, the finest rubies were mined in Myanmar and it is from there that the term Burmese ruby began to describe the finest rubies.
Ruby is the birthstone for July and the gem for the 15th and 40th anniversaries
Sapphire gets its name from the Latin term 'Sapphiru' which means blue. Throughout the ages, they were adorned by royalty and regarded as a symbol of good fortune, virtue, wisdom and holiness. In ancient Greece and Rome, kings and queens believed that blue sapphires protected them from any harm. Even in the Middle Ages, the priests wore blue sapphires to symbolize Heaven, and believers were sure that the gem attracted heavenly blessings. In other times and places, people kept sapphires in order to guard purity, make peace between enemies, influence spirits, and reveal the secrets of prophecies.
Sapphires come in an array of colours, from a vibrant sky blue, to navy blue, yellow, and the pink of sunrise and sunset. Sapphires also come in shades of Green, White, Colorless, Orange, Brown and Purple.
Intensely coloured and smooth as velvet, rare sapphires from Kashmir set the standard for their shade of blue.
Sapphire with a mid-colour, concentrated blue hue that remains the same under varying lighting conditions is the most valuable.
Hardness - 9 on Mohs scale
Specific Gravity - 4.00
Sapphires belong to the family of minerals known as corundum. After diamonds they are one of the strongest gemstones in nature.
Because of their durability, synthetic sapphire is used for the windows of supermarket scanners and space crafts. Although Sapphire is a hard and durable gem, but may still chip or get fractured if handled very roughly.
Like the Ruby, the Star sapphire is rare variety that also shows the rare phenomenon called 'asterism' under specific lighting. A six-rayed star will appear to float across the surface of the stone. The effect is best viewed under a direct light source and while tilting and rotating the stone from different angles. This optical phenomenon is quite rare, being only found in a tiny percentage of the sapphires mined around the world. Star sapphires can occur in any color, but the most common colors are blue, black and pink.
Sapphires can be found in several colours. The most prominent gemstone colours apart from blue are as follows:
Yellow Sapphire - (is often referred to as the "Golden Sapphire" if the yellow is a deep one) - Yellow sapphires are wide-ranging in colour, from greenish yellow to orangish yellow. A medium, vibrant canary yellow is the optimum choice for a yellow sapphire. Due to fewer inclusions compared to others, yellow sapphires are renowned for having high clarity than blue, pink or padparadscha sapphires. Readily available in specialty cuts, yellow sapphires are found across Africa, Australia and Asia, with Sri Lanka being the primary source.
Pink Sapphires - This variety ranges from a pale baby pink to an intense magenta. Currently, the most prized pink sapphires have a saturated red hue with a medium tone – they are often described as "hot pink" or "bubble-gum pink". Usually, these gems are found in Madagascar, Sri Lanka, Myanmar and East Africa.
White Sapphire – Also known as "leucosapphire" and are not white, but transparent and colorless. It is also the purest and rarest form of corundum, since it lacks the trace elements that color other sapphires. The gem is used as a substitute for diamond. Clarity is the distinguishing factor to the stone's status as a gem.
Purple Sapphire & Violet Sapphire - Though often confused, these two colours have distinct hues. A blended hue, purple is red with a mixture of blue. On the other hand, violet is a mixture of blue with purple. These colors are more obscure because of other purple and violet gemstones. However, sapphires are highly durable and vivid compared to other stones of the same color, apart from having good clarity. Purple and violet sapphires come from Sri Lanka, Kenya, Tanzania, Madagascar, and Myanmar.
Orange Sapphires - Light pastel oranges to vivid reddish oranges is the range of these gems. A blend of red and yellow hues, orange sapphire was initially underrated gem, but lately orange sapphire has gained popularity owing to the colour's prominence in fashion. Orange sapphires with an attractive color are rare in any size, so stones that are slightly or moderately included are considered valuable gems.
These gems are found in Australia, Sri Lanka, Tanzania, Kenya, and Madagascar.
Padparadscha Sapphire - The term "padparadscha" comes from the Singhalese word for aquatic lotus blossom with a rare salmon colour. Some padparadscha sapphires are not entirely salmon coloured, but have are a mix of pink and yellow.
The light tones of padparadschas reveal any inclusions thereby making clarity is an important element. A padparadscha’s delicate colour can easily be dulled by even the slightest amount of cloudiness.
Padparadschas have unusual, asymmetrical cuts. They are mainly found in Sri Lanka, as well as Madagascar and Tanzania.
Barring a few inclusions, sapphires generally have good clarity.
There are various processes to change the color, outward clarity, or improve the durability of gems. To improve the color and clarity, most natural sapphires undergo heat treatment. This practice, adopted across the industry results in a permanent enhancement that helps protect against accidental chipping or breakage.
Sapphires have been found over the globe in countries as far as Kashmir, China, Cambodia, Sri Lanka, Thailand, Burma, Australia, and Brazil.
Sapphire is the birthstone for September and the gem of the 5th and 45th anniversaries.
The word tanzanite comes from Tanzania since the world's sole tanzanite deposit of commercial importance is in northern Tanzania. According to the oldest story, in 1967 a Masai tribesman discovered a horde of highly transparent, deep blue crystals popping out of earth in Merelani, an area in northern Tanzania. Recognizing its potential as an international seller, Tiffany and Company become its main distributor. The gem was named after the country by Tiffany and promoted under it. This transparent blue to violet to purple gem owes its instant popularity to its vivid color, high clarity, and potential for large cut stones.
Tanzanites are found in shades of blue to bluish-purple to bluish-violet.
Hardness - 6.5 on Mohs scale
Specific Gravity - 3.35
Tanzanite is pleochroic, which means that it shows different colours depending on the viewing angle. The vivid blue of tanzanite matches up to a fine sapphire making tanzanite a very desirable gemstone. The tanzanite is regularly heated to enhance the fine blue and violet hues since the colour is highly sought after.
Eye-visible inclusions decrease the value of tanzanite, particularly in lighter colored stones.
All of tanzanite is subject to heat treatment today. This is in order to enhance or produce the desired blue. This treatment is across the industry and should be expected by customers.
All of the mines are located in an area of about eight square miles in the Merelani Hills, near the base of Mount Kilimanjaro and the city of Arusha in Northern Tanzania.
Tanzanite is a birthstone for December, Tanzanite is also the gem for a 24th anniversary.
Rubellite, or “Ruby Like” is a red variety of tourmaline. In the past, Rubellite was often mistaken for a Ruby or a Sapphire, due to its deep and brilliant Reds. While the Tourmaline gained prominence in the 20th Century, it was quite famous in classical times. In the 17th century, Peter the Great allegedly custom-made several items of ‘Ruby' jewelry for the Russian Imperial Court that were later found to be Rubellite. Today, Rubellite is the most sought after variety of Tourmaline due to its intense sheen and opulent colors. It is believed that rubellite helps one find courage and strength to face.
The color ranges from Reddish, Pinkish and Violetish Hues.
Hardness - 7 - 7.5 on Mohs scale
Specific Gravity - 3.06
It is relatively a hard stone. Rubellite is the only other gem known to occur in such a rich, dark red color, apart from ruby and red spinel and hence very valuable. It is a magnificent gem, very rare, particularly due to scarcely any ‘eye clean' material. Its sheen is glassy, it ranges from transparent to translucent.
Rubellite tourmalines grow in an environment rich in liquids, and some of which are usually captured as inclusions during crystal growth. The most common inclusions resemble thread-like cavities, parallel to the length of the crystal. Stones might have long and thin liquid/gas inclusions, reflective gas-filled fractures and color zoning.
The pink to red coloured Rubellite stones are changed by irradiation to improve their colour. Heat treatments also enhances the colour of the stones – darker stones can be lightened whereas some brownish-red stones can be made red or pink.
Afghanistan, Brazil, East Africa, Nigeria, Mozambique, Madagascar, U.S.A.
Rubellite is the birthstone for October. Rubellite is also the gem for the 17th year anniversary.
The name “aquamarine” comes from the Latin words: aqua, meaning “water,” and marina, meaning “of the sea.” Anselmus de Boodt first used the term “aquamarine” in his gemological work, “Gemmarum et Lapidum Historiia”. As opposed to the 19th century, where sea green varieties of the stone were most popular, today, the bluer the color, the more valuable the stone. Roman legend states that the stone exhumes an atmosphere of young love: “When blessed and worn, it joins in love, and does great things.” The Greeks and the Romans considered the aquamarine as the sailor's gem the safe and prosperous passage across stormy seas.
Like seawater, aquamarine can be light-blue, dark-blue, blue-green and green-blue.
Hardness - 7.5 - 8 on Mohs scale
Specific gravity - 2.72
Known for its transparency and clarity, aquamarine, and other types of beryl, are quite durable, ranging from 7.5 to 8 on the Mohs scale of mineral hardness. A deeply saturated blue is the most valuable of colours.
Aquamarine can be used for jewelry as long as it is protected it against scratching and hard knocks.
Aquamarine should not be exposed to heat but the color is stable against light exposure. It can be attacked by hydrofluoric acid.
Most cut gems are eye-clean. Several samples are available without visible inclusions.
Most commercially available aquamarines are already heated. They can even be treated at the mine before they reach the market. This applies to finished stones as well as rough.
Found mainly in Brazil, Madagascar, Russia, Afghanistan, India, Pakistan, Nigeria, Zambia, Mozambique and USA.
Aquamarine is the birthstone for March and the gem of the 19th wedding anniversary.
The name, “Peridot” comes from the Arabic word “faridat” that means “gem.” With an estimated history of 5,000 years, it was first mined on the island of Zagbargad, now known as Zebirget, in the Red Sea. Since ancient times till the Middle Ages, it was considered symbolic to the sun. It became a popular choice for jewellery in Europe during the Baroque period, Victorian jewellery during the mid-to-late 1800's, and later for Art Nouveau jewellery.
Most stones are yellowish-green, with the best being a pure grass green.
Hardness - 6.5 - 7 on Mohs scale
Specific gravity - 3.34
Peridot's color comes from the basic chemical composition of the mineral itself and not from minor traces of impurities. While the shades of green may vary from light yellowish to dark brownish-green, it is few of those gemstones found only in one colour.
Considerably softer than many other gems, care should be taken to prevent scratches on the stone. It also has a brittle built. It is also known to burst under high stress so such settings should be avoided.
Fine peridot is generally eye clean. Tiny black spots might be visible with magnification.
Peridot is not typically treated or enhanced in any way.
Found mainly in Australia, Mexico, Sri Lanka, South Africa, Tanzania, China, Burma, Arizona, USA, Pakistan, Afghanistan.
Peridot is the birthstone for the month of August. It is also the stone given to celebrate the 16th year of marriage.
A rare variety of the mineral chrysoberyl, gem aficianados call alexandrite “Emerald by day, ruby by night.” The first alexandrites, originally discovered in Russia's Ural Mountains in 1830s exhibited vibrant hues, vivid colour changes and fine quality. Named after the young Alexander II, most of alexandrite comes from Sri Lanka, East Africa and Brazil.
Color - Fine alexandrite is green to bluish green in daylight and red to purplish red in incandescent light. Alexandrite can show both color changes and cat's eye: two phenomena in one gem.
Hardness - 8.5 on Mohs scale
Specific gravity - 3.73
Known as 'alexandrite effect,' the change in color can be observed under certain lighting conditions, mainly under daylight and luminescent lighting. Alexandrite is also a pleochroic gemstone. Which means that it can exhibit a number of different shades depending on the angle from which its being viewed. Typically, alexandrite displays an emerald-green color in daylight, and raspberry-red under incandescent lighting.
Alexandrite and chrysoberyl in general are very durable thereby suitable for everyday wear.
Good quality alexandrite has few inclusions and very rarely it would occur that needle like inclusion would create a cat's eye.
Alexandrite gemstones are usually organic, but imitation stones do exist. Seldom, alexandrite stones may be dyed or oiled.
Found mainly in Russia, Sri Lanka, Brazil, Burma, Madagascar, USA.
Alexandrite is a birthstone for June, along with pearl and moonstone. Alexandrite is also the gem for the 55th wedding anniversary.
Renowned geologist, Abraham Gottlob Werner first found the chrysoberyl species in 1789. Their history dates back to first-century Rome. Sri Lanka and India are the two most likely sources for chrysoberyl cat's-eye from this period. The gem suddenly was in great demand just after the British Duke of Connaught (1850-1942), third son of Queen Victoria, gave a cat's-eye engagement ring to Princess Louise Margaret of Prussia in 1879.
The range of Chrysoberyl cat's eye is everything between greenish yellow to light honey. It is also found in shades of mint-green to darker brownish-green.
Hardness - 8.5 on Mohs scale
Specific Gravity - 3.7 - 3.78
Chrysoberyl cat's eye shows a rare optical trait known as 'chatoyancy'. The gem reflects light in a manner that looks like the slit of a cat's eye, hence the name.
Albeit hard and durable, it can be easily scratched by harder gems, like sapphire and diamond.
Cat's-eye chrysoberyl's "eye" is caused by fibrous inclusions that reflect the light. Faceted chrysoberyl is transparent, with few visible inclusions.
Chrysoberyl cat's eye is not typically treated or enhanced in any way.
Chrysoberyl is a very rare mineral and gemstone quality deposits of cat's eye are even rarer. Most chrysoberyl cat's eye is sourced from Brazil, China, India, Sri Lanka and Zimbabwe. Some other notable sources include Burma (Myanmar), India, Tanzania, Madagascar, Pakistan, Russia and the United States.
Cat's Eye was the traditional Birthstone for June.
This gem was a symbol of love and hope in ancient Rome. It was christened—opalus—meaning “precious stone” by the Romans. It was believed as possessing all the virtues of each of the gemstones whose colours were represented as well as providing luck during the Middle Ages.
Till the late 19th century Slovakia was the primary source, but large deposits were found in Australia in 1887, including the rare and valued black opal.
Opal's spectacular play-of-color can display all the colors of the rainbow.
Hardness - 5 to 6.5 on Mohs scale
Specific Gravity - 2.15 (+0.08, -0.90)
Known as ‘play of colour', opal is known for the ability to deflect light which results in rainbow-like colors that change with the angle of observation. Popular for its vivid body colour, fire opal can sometimes display minor color play. Common opal is usually opaque, rarely translucent, and lacks play of color.
Opals are delicate gemstones with their greatest weakness being the water content. If an opal is left to dry, it will crack and fade. They also scratch easily.
Opal gemstones can be transparent to opaque. The former is typically more valuable than the latter. Most opals have some visible internal fractures or inclusions such as patches or matrix rock inclusions.
Opal is typically untreated, but it may be infused with oil, wax, or plastic to enhance color and stability.
Found mainly in Australia, Brazil, Mali, Japan, Russia, USA, Mexico.
Opal is an October birthstone.
The earliest known spinel dates back to 100BC and was discovered in a Buddhist tomb near Kabul, Afghanistan.
Blue spinels from 51BC to 400AD have been found in England. Sometimes mistaken for a ruby or sapphire, spinel is a gemstone worthy of recognition.
With a diverse range of colours like rose pink to rich red; lavender to deep violet; light to deep blue, orange, yellow, brown and black, the most valued spinel colors are bright red, cobalt blue, and vivid pink and orange.
Hardness - 8 on Moh's scale
Specific Gravity - 3.60
Spinel has a variety of stunning hues and also exhibits optical phenomena like asterism and color-change. It is generally under-appreciated compared to other colored stones, thereby becoming more affordable. Owing to its hardness, spinel does not scratch easily.
Spinel with no visible inclusions is the most valuable.
Usually spinel is untreated.
Spinel occurs with ruby and sapphire, and significant deposits have been found in Cambodia, Myanmar, Sri Lanka and Thailand. Other locations where spinel deposits have been found are Afghanistan, Australia, Brazil, Madagascar, Nepal, Nigeria, Tadzhikistan, Tanzania and the USA.
Derived from the Sinhalese word, "turamali" meaning "stone with various colours" tourmaline is an extremely versatile stone.
In the 1500s, a Spanish conquistador washed the dirt from a green tourmaline crystal in Brazil and confused the vibrant gem with emerald. It wasn't until the 1800s that scientists recognized tourmaline as a distinct mineral species.
Tourmaline's rainbow colors are highly intense.
Hardness - 7 to 7.5 on Mohs scale
Specific Gravity - 3.06 (+0.20, -0.06)
Tourmaline gemstones are quite tough and durable. But they need to be wiped down frequently as they tend to attract more dust than other gemstones.
Pink to red tourmaline often has more visible inclusions than green to blue varieties.
Most tourmaline is completely untreated. However, some stones may be heated to improve colour and clarity. Yellow, pink and red varieties of tourmaline may be irradiated to enhance colour, although irradiation is nearly impossible to detect and does not normally affect value. Heavily included rubellite and paraiba tourmaline may be clarity enhanced. The color of many darker stones can be lightened.
Majority of tourmaline deposits come from Minas Gerais and Bahia, Brazil. Other notable sources include Afghanistan, Australia, Burma (Myanmar), India, Italy, Madagascar, Malawi, Mozambique, Namibia, Nepal, Nigeria, Pakistan, Russia, Sri Lanka, Switzerland, Tanzania, the United States, Zaire, Zambia and Zimbabwe.
Tourmaline is a birthstone for October, along with opal. Tourmaline is also the gem of the eighth anniversary.
George D. Kunz, a famous American gemologist and buyer for Tiffany & Company first discovered pink morganite in California, USA in 1910 by. Initially, it was simply referred to as 'pink beryl', but in 1911, it was renamed by George Kunz in honor of John Pierpont (J.P.) Morgan, the American banker and avid gemstone collector. It is a precious stone due to its rarity.
Morganite is available in shades of Pink, Rose-lilac, Peach and Orange
Hardness - 7.5 to 8 on Mohs scale
Specific Gravity - 2.80 to 2.91
Morganite's color can range from pale pink to violet, salmon or peach. It is quite hard and durable. Morganite is denser compared to other beryls. Unlike emerald which tends to be heavily included, it is quite clean. In most cases, morganite can be easily distinguished from other pink stones by its brilliance and shine, combined with its hardness, durability and excellent clarity.
Faceted morganite usually has no eye-visible inclusions. Although it can contain liquid inclusions that contain gas bubbles and possibly also solid phases.
Morganite is often found unheated and free of any enhancement. However, many stones today may be routinely heat treated to improve color and remove unwanted yellow tones.
The two most significant deposits are found in Brazil and Madagascar. Other notable sources for fine gem-quality morganite include Afghanistan, China, Mozambique, Namibia, Russia, Zimbabwe and the USA.
Kunzite is named after George Kunz, an American mineralogist and the former vice president and buyer for Tiffany & Co. It was discovered in Connecticut, U.S. It has proven to be a highly desirable gem.
The color ranges from the shades of beautiful pink to lilac.
Hardness - 6.5 to 7.0 on Mohs Scale
Specific Gravity - 3.18
Prolonged exposure to direct sunlight causes kunzite's color to fade. Unlike other pink colored stones, kunzite is often found in large sizes. The glint and hardness is similar to quartz, making it softer than pink sapphire and spinel.
Kunzite has excellent transparency. Some stones can show frequently aligned inclusions such as tubes or fractures.
Most kunzite is not typically treated or enhanced in any way. However, some brownish and green-violet stones may be heated to improve color.
The most important deposits of kunzite are from Brazil, Minas Gerais, Afghanistan and Pakistan. Other sources include Madagascar, Myanmar and the USA. Smaller gem quality deposits have also been found in Canada, Russia, Mexico, Sweden and Western Australia.
Some consider kunzite to be an alternate birthstone for February.
The name "turquoise" is derived from the French "turqueise" meaning "Turkish stone." Beads have been found in Mesopotamia (present-day Iraq) that dating back to 5000BC. Records suggest that Native Americans have been using turquoise since 1000AD, and it has been mined in Persia (Iran) and Egypt sincethe last 3000 years. Turquoise comes in a wide range of sizes and is plentiful. It is used for beads, cabochons, carvings, and inlays.
Blue to Green
Hardness - 5 to 6 on Mohs scale
Specific Gravity - 2.76
Turquoise stands out due to its distinctive blue-green colour and waxy to matt luster. Its solidity distinguishes it from imitations or synthetic materials. Pure blue turquoise is rare since turquoise is typicallyintermingled by brown, dark-grey or black veins. These veins can either be the host rock or other minerals. "Turquoise matrix" are turquoises with veins.
Sensitive to heat, if turquoise is exposed to 250 degree Celsius heat, the colour will turn a dull green.
Turquoise is translucent to opaque, the former being rare. Most turquoise has dark-grey, brown or black veiny inclusions of matrix or other minerals. Inclusions are brown or black veins which are either sparse or dense.
Since turquoise is a porous material, it is sometimes infused with polymers, wax or plastic to enrich the colour and harden the surface. This is also achieved by using oil or paraffin, colours or copper salt.
The best quality turquoise is found in Northeast Iran. Turquoise deposits can also be found in Afghanistan, Argentina, Australia, Brazil, China, Israel, Mexico, Tanzania and Arizona, USA.
Turquoise is the traditional birthstone for the month of December and the gem of the 11th anniversary.
The expert consensus is that the name “topaz” comes from Topazios, the old Greek name for a small island in the Red Sea.
Some scholars also trace the origin back to Sanskrit (an ancient language of India) and the word topas or tapaz, meaning “fire.”
Topaz was considered as strength-inducing by the ancient Greeks. For centuries, people in India believed that topaz worn above the heart assures a long life span, beauty and intelligence.
Blue, yellow, orange, brown, pink to red to purple red, light green and colorless.
Hardness - 8 on Mohs scale
Specific Gravity - 3.53
Topaz is shaped like large crystals: the biggest are kilos, not carats. Faceted topaz takes a high polish making it slippery to the touch.
Topaz is pleochroic, displaying diverse colors in different directions.
Like diamond, topaz has perfect cleavage, meaning the force of a single blow could cause it to split. Therefore, protected bezel settings are better than pronged settings, for rings that are worn daily. Topaz's hardness (8 on the Mohs scale) makes it durable and scratch resistant.
Topaz is transparent to translucent. It displays high clarity with few inclusions and can be examined by the naked eye to be found "eye clean"
Topaz is often enhanced to produce the most eye-catching colours.
Deposits of topaz have been found in Brazil, Afghanistan, Australia, Myanmar (Burma), China, Germany, Japan, Madagascar, Mexico, Namibia, Nigeria, Pakistan, Russia, Zimbabwe, Sri Lanka, Ukraine and the USA. Natural light-blue topaz is found in Northern Ireland and the UK. Large topaz crystals have been discovered in Minas Gerais (Brazil) and Ukraine.
Precious topaz is a birthstone for November and blue topaz is a birthstone for December. Blue topaz is the gem of the 4th anniversary and Imperial topaz is the gem of the 23rd anniversary.
Garnet necklaces decked the necks of Egypt's pharaohs; in ancient Rome, signet rings with carved garnets were used to stamp the wax that secured important documents.
Centuries later, in Roman scholar Pliny's time (23 to 79 AD), red garnets were among the most widely traded gems. In the Middle Ages, red garnet was the preferred gem of the clergy and nobility alike.
Red garnet's availability increased with the discovery of the famous Bohemian garnet deposits in central Europe around 1500.
Garnet is available in a several colours like yellow, orange, peach, green, red, purple, blue (rare), brown and pink. Red is the most common colour, with blue being the rarest. Garnet also occurs in colour-changing varieties.
Hardness - 6.5 - 7.5 on Mohs scale
Specific Gravity - 3.47-4.15
Garnet is a family of stones having varieties differing in color and in their constituents. The most popular are:
Almandine - Almandine garnet can range from pure red, reddish-orange and slightly purplish-red to dark, brownish-red. Almandine garnet with pure, deep red colors are highly valuable.
Pyrope - Pyrope is the most well-known gemstone form of Garnet. It has a distinctive red colour resembling that of a ruby. Pyrope garnet is usually inclusion free. Pyrope garnet has a glossy lustre.
Rhodolite - Rhodolite garnets can be rose pink, purplish-pink, raspberry-red or purplish-red. The most sought after colour is raspberry red. It is a mix of pyrope and almandine in composition. Premium quality rhodolite garnets do not have any visible inclusions and display a vitreous lustre.
Tsavorite - Tsavorite is a trade name for the emerald-green variety of Grossular garnet originating in Africa. The best Tsavorite color is a deep emerald green. It usually has far lesser inclusions and can be flawless.
Hessonite - Hessonite garnet ranges in color from honey-yellow to orange-brown and brown-red. The most common impurities are honey-colored inclusions.
Garnet exhibits a glassy lustre. Garnets are generally clean stones, however, almandine garnets sometimes have asbestos fibre inclusions. These inclusions cause asterism (a star effect), which is treasured due to its rarity. Some varieties of Garnet may have eye visible inclusions.
Garnet is not artificially enhanced in any way.
Rhodolite: Brazil, Burma (Myanmar), China, Kenya, Madagascar, Mozambique, Sri Lanka (Ceylon), South Africa, Tanzania, the USA and Zimbabwe.
Pyrope: China, Madagascar, Myanmar (Burma), South Africa, Sri Lanka, Tanzania, Brazil, India, Thailand and the USA.
Almandite: Brazil, India, Madagascar, Sri Lanka and the USA. Smaller deposits exist in Austria and the Czech Republic. Almandine garnet star-stones are found in India and the USA.
Hessonite: Brazil, Canada, Madagascar, India, Tanzania and the USA.
Tsavorite: Kenya and Tanzania.
Garnet is the birthstone for January and the gem for the second anniversary.
Having being used for thousands of years Coral is an ancient gemstone. Coral is one of the seven treasures in Buddhist scriptures and Tibetan Lamas use coral rosaries.
In the 18th century, it was widely used as an inlay in Japanese netsukes. Coral is used as cabochons and beads. It is also shaped into small carvings such as flowers for pins and brooches and stranded into spiky, dangling necklaces.
The most valued coral typically displays a range of warm pinkish to red colors, including light-red to salmon, and medium-red, to deep ox-blood red; color is known to fade when worn.
Hardness - 3 - 4 on Mohs scale
Specific Gravity - 2.6 - 2.7
Coral is naturally dull; polishing brings out its glassy luster. Coral gemstones are either solid or porous, depending on the polyp formation. It is very soft and brittle and is prone to both scratches and chipping.
Precious coral is typically translucent to opaque. It can have color zones or swirls, with white, pink, orange, and red being the most prominent. When unworked, it has a naturally dull, matte luster.
Natural coral is typically untreated, but some materials may be dyed or bleached to achieve a more valuable color.
Though precious coral is found in locations all around the world, Torre del Greco (near Naples, Italy) has been the top coral trading center for over 200 years, processing nearly 75% of the entire world's supply of coral. Most of the precious coral available today is harvested from the western Mediterranean Sea, especially in Sardinia. Notable deposits are also found in the Red Sea, the Bay of Biscay, the Malaysian Archipelago, the Midway Islands, Japan, Taiwan, Australia and the Hawaiian Islands. Precious coral from Hawaii, coastal Japan, the Mediterranean and the Red Sea is considered to be the finest coral of today.
Coral along with diamond is the birthstone for April. Coral is also the gemstone for the 35th anniversary.
In Europe and the Middle East the different varieties of quartz were used for various types of jewelry and hardstone carving, including engraved gems and cameo gems, rock crystal vases, and extravagant vessels. The tradition continued until the 19th century, when it largely fell from fashion except jewelry. Quartz is the second-most abundant mineral in Earth's continental crust. There are many different varieties of quartz, several of which are semi-precious gemstones.
Colourless, white, gray, yellow to brown to black, violet, pink
Hardness - 7 on Mohs scale
Specific Gravity - 2.63 - 2.65
Quartz is one of the most common minerals on earth, and its abundant colors produce many gemstone types.
Amethyst - Amethyst is the most popular and valuable Quartz gemstone. With a range of light to dark purple, amethyst appears in large flawless crystals. Since it is found in abundance, amethyst is usually clean and free of inclusions, with stones of all sizes being faceted.
Citrine - Citrine is available in yellow, orange, or reddish-brown colours. Light yellow Citrine is mainly known as Lemon Quartz in the gem trade. Citrine is also found in large crystals, with gems of all sizes being cut. Purple Amethyst mixed naturally with golden Citrine is called "Ametrine"
Lemon Quartz - It is closely related to citrine quartz, but is yellower than citrine that has heavier orange tones. Generally, clear Quartz is irradiated to produce an intensely colored yellow gemstone resulting in this variety. Lemon Quartz has become prominent lately.
Smoky Quartz - Ranging in color from light brown to black, it is the "smoky" variety of quartz. Frequent inclusions are rutile needles. It is rarely opaque in spite of its colour.
Rose Quartz - As the name suggests, the color of this variety is usually soft, ranging from very light pink to medium pink. Rose quartz can be cloudy, which deepens its color. Transparent rose quartz crystals are very rare.Larger stones can be faceted
Rock crystal - This is a colorless variety of quartz. It has a vitreous luster and inclusions consist of goethite, gold, pyrite, rutile or tourmaline. Material that can be cut is rare.
Natural pearls have been coveted symbols of wealth and status for thousands of years. A Chinese historian recorded the oldest written mention of natural pearls in 2206 BC. Royalties from Asia, Europe and elsewhere treasured pearls.
During Christopher Columbus' expeditions to the New World, he constantly encountered native people adorning pearls. But, within a hundred years, the natural sources of pearls started declining.
Pearl culturing first began in China centuries back, and Japanese pioneers successfully produced whole cultured pearls around the beginning of the twentieth century. From the 1930s till the ‘80s, pearl culturing diversified across the globe.
White, black, gray, yellow, orange, pink, lavender, green, blue.
Hardness - 2.5-3.0 on Mohs scale
Specific Gravity - 2.60-2.85
Pearl is an organic gem.
There are two types of pearls: natural and cultured pearls.
Pearls are formed when a mollusk produces layers of nacre around some type of irritant inside its shell. In natural pearls, the irritant may be another organism from the water. In cultured pearls, a mother-of-pearl bead or a piece of tissue is inserted (by man) into the mollusk to start the process.
Natural pearls are extremely rare. Unfortunately, today, most have already been harvested.
Cultured Pearls - are grown in pearl farms.
There are four major types of cultured whole pearls:
Akoya - This is the most popular amongst jewelry customers. Japan and China both produce saltwater akoya cultured pearls.
South Sea - Australia, Indonesia, and the Philippines are leading sources of these saltwater cultured pearls.
Tahitian - These saltwater cultured pearls are primarily cultivated around the islands of French Polynesia (the most familiar of these is Tahiti). They range from white to black.
Freshwater - These are usually cultured in freshwater lakes and ponds. They're produced in a wide range of sizes, shapes, and colors. China and the US are the leading sources.
The lustre of pearls depends on the quality of the nacre. Pearls should have the distinctive shiny lustre and their surface should show sharp and bright reflections. The surfaces of good quality pearls are smooth and blemish-free
Pearls are often bleached to lighten and enhance their colour.
Pearls are found and cultured in waters over the world. Natural sea pearls are found in Australia, Japan, Central America, the Persian Gulf, the Gulf of Manaar, the coast of Madagascar, Burma, the Philippines, the South Pacific Islands (including Tahiti and Fiji) and South America.
Natural river pearls are found in Asia, Europe and North America.
Sources of cultured seawater pearl include Southeast Asia, Australia, China, French Polynesia, Japan, South Pacific Islands (including Tahiti and Fiji) and the Philippines.
Cultured freshwater pearl sources include China and Japan.
Pearl is the birthstone for June and the gem of the third and thirtieth anniversaries.
Diamonds have been a source of fascination for centuries. The word "diamond" comes from the Greek word “Adamas” meaning “Unconquerable".
The first recorded history of the diamond dates back some 3,000 years to India, where it is likely that diamonds were first valued for their ability to reflect light.
In the Middle Ages, the worth of a diamond was more important than the mystical powers surrounding them. The popularity of diamonds surged during the middle ages, with the discovery of many large and famous stones in India, such as the Kohinoor and the Blue Hope.
On October 2nd 1979, geologists found the Argyle pipe near Lake Argyle: the richest diamond deposit in the world. Since then, Argyle has become the world's largest volume producer of diamonds, and alone is responsible for producing over a third of the world's diamonds every year.
Colorless, white, brown, yellow, pink, red, blue and black
Physical and Optical Properties
Hardness - 10
Specific gravity - 3.52
Diamond is the only gem composed of one single element: carbon.
Most diamonds are formed more than a billion years ago, deep in the earth's mantle.
The 4Cs, created by GIA, are believed to be the global benchmark of diamond quality.
Diamond cut is crucial to increase its beauty because a well-cut diamond reflects light to maximize the stone's brilliance. A diamond with perfect color and clarity could nevertheless have poor brilliance if it is not well cut.
Diamonds have a unique ability to manipulate light efficiently. This exceptional ability can be revealed and exploited only by cutting and polishing the diamond very accurately.
Diamonds are found in a spectrum of colours, from colorless and transparent stones to ink black ones. Varying degrees of yellow or brown color is common in most of the diamonds and the smallest difference in color makes a substantial difference in value. A truly colorless diamond is extremely rare and most valuable.
Most diamonds appear white to the naked eye, but they all include trace amounts of yellow or brown color. The color scale goes from D to Z (no diamond of color grade A, B or C has ever been found), with D being the most white and Z being the most yellow. The best way to see the true color of a diamond is by looking at it against a white surface.
The clarity of a diamond refers to a diamond's clearness or purity.
The most common types of inclusions include Crystals, Tiny Bubbles representing small minerals that were absorbed into the diamond while it was growing, Internal Graining, Needles, Knots, Chips, Cavities, Cleavage, Feathers, and Clouds. Although many of these flaws are not visible to the naked eye, but under magnification, they become noticeable. These slight flaws give every diamond a unique feature but they also affect the beauty and value of the diamond.
Diamond's clarity is based on the number, size, nature, and location of imperfections on the finished stone. Diamond with higher clarity is more valuable in comparison to diamond that contains numerous inclusions because it is less brilliant due to inclusions interfering with light passing through it.
The GIA diamond grading scale is divided into six categories and eleven grades.The clarity categories and grades are:
The term "Carat" refers to the weight of a diamond. One carat is equivalent to 200 milligrams. Each carat is divided into 100 points. Therefore, ¼ carat diamond is considered as 25 points or cents and ½ carat diamond is considered as 50 points or cents and so on. When we consider all four Cs, that determine the value of the diamond, we can find Carat weight quite easily by using a delicately balanced scale capable of weighing extremely small stones.
Champagne, cognac and colorless 'white' diamonds are typically untreated. However, they may be artificially enhanced. Laser drilling can be used to remove inclusions; fissures and cracks may be artificially filled with glass. Several fancy colors occur naturally, but most are produced through irradiation or high pressure / temperature treatment.
Approximately half of the world's diamonds come from Central and Southern Africa. The production levels of diamonds vary year by year, but as of 2010, the top diamond producers were Russia, Botswana, Congo, Angola, South Africa, Namibia, Guinea, Ghana, Australia and Canada. There have also been significant deposits found in India and Brazil. Canada has recently become a main commercial source for fine white diamonds.
Diamond is the birthstone for April. Diamond is also the gem that marks the 60th and 75th wedding anniversaries.