Gems in Sri Lanka

8/10/2019 Gems in Sri Lanka

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Gems in Sri Lanka


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Content 1.Gems of Sri Lanka 2.Gems of Highlights in Sri Lanka 1.Sapphir 10.Topaz 2.Ceylon Sapphir 11.Star stones 3.Ruby 12.Citrine 4.Alexandrite 13.Topaz 5.Aquamarine 14.Quartz 6.Cats eye 7.Peridot 8.Garnet 9.Amethyst


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Gems of Sri Lanka

Traditional Gem Fields of Sri Lanka Sri Lankas gem industry has a very long and colorful history. Sri Lanka was affectionatel y know n as

Ratn a-Dweepa which means Gem Island. The name is a reflection of its natural wealth. MarcoPolo wrote that t he island had the best sapphires, topazes, a methy sts, and othe r gems in theworld. [1] Ptolemy , the 2nd century astronomer recorded that beryl and sapphire were the mainstayof Sri Lank as gem i ndustry. Records from sailors that visited the island states that they brought backjew els of Serendib . Serendib was t he ancient na me given to the island by middle easternand Persian traders that crossed the Indian Ocean to trade gems from Sri Lanka to the East duringthe 4th and 5th century.

Sri Lanka, ge ologically spe aking is an extremely old country. Ninety percent of the rocks of theisland are of Precambrian age, 560 mil lion to 2,400 mi llion years ago. The gems form in sedimentary residual gem deposits, eluvial deposits , metamorphic deposits, skarn and calcium-rich rocks. Other gems are of magmatic origin.

Residual deposits are mainly found in flood plains of rivers and streams. The metamorphic types ofgems constitute 90% of the gem de posits in Sr i Lanka. Sri Lanka has the highest density of gemdeposits compared to its landmass. Ratnapura contains the most gem deposits and derived itsname from the gem industry. Ratnapura means city of gems.

The blue sapphires from Sri Lanka are known as Ceylon Sapphire. Ceylon Sapphires are reportedlyunique in colour, clarity and lustre compared to the blue sapphires from other countries.
http://en.wikipedia.org/wiki/Sri_Lankahttp://en.wikipedia.org/wiki/Gemstonehttp://en.wikipedia.org/wiki/Marco_Polohttp://en.wikipedia.org/wiki/Marco_Polohttp://en.wikipedia.org/wiki/Marco_Polohttp://en.wikipedia.org/wiki/Marco_Polohttp://en.wikipedia.org/wiki/Gems_of_Sri_Lankahttp://en.wikipedia.org/wiki/Ptolemyhttp://en.wikipedia.org/wiki/Berylhttp://en.wikipedia.org/wiki/Sapphirehttp://en.wikipedia.org/wiki/Gems_of_Sri_Lankahttp://en.wikipedia.org/wiki/Ptolemyhttp://en.wikipedia.org/wiki/Berylhttp://en.wikipedia.org/wiki/Sapphirehttp://en.wikipedia.org/wiki/Serendib_(old_name)http://en.wikipedia.org/wiki/Persian_empirehttp://en.wikipedia.org/wiki/Persian_empirehttp://en.wikipedia.org/wiki/Persian_empirehttp://en.wikipedia.org/wiki/Serendib_(old_name)http://en.wikipedia.org/wiki/Indian_Oceanhttp://en.wikipedia.org/wiki/Persian_empirehttp://en.wikipedia.org/wiki/Indian_Oceanhttp://en.wikipedia.org/wiki/Precambrianhttp://en.wikipedia.org/wiki/Sedimentaryhttp://en.wikipedia.org/wiki/Sedimentaryhttp://en.wikipedia.org/wiki/Precambrianhttp://en.wikipedia.org/wiki/Eluvial_deposithttp://en.wikipedia.org/wiki/Metamorphic_rockhttp://en.wikipedia.org/wiki/Skarnhttp://en.wikipedia.org/wiki/Sedimentaryhttp://en.wikipedia.org/wiki/Magmahttp://en.wikipedia.org/wiki/Magmahttp://en.wikipedia.org/wiki/Eluvial_deposithttp://en.wikipedia.org/wiki/Metamorphic_rockhttp://en.wikipedia.org/wiki/Skarnhttp://en.wikipedia.org/wiki/Magmahttp://en.wikipedia.org/wiki/Ratnapurahttp://en.wikipedia.org/wiki/Ratnapurahttp://en.wikipedia.org/wiki/Sapphirehttp://en.wikipedia.org/wiki/Sapphirehttp://en.wikipedia.org/wiki/Ratnapurahttp://en.wikipedia.org/wiki/Magmahttp://en.wikipedia.org/wiki/Skarnhttp://en.wikipedia.org/wiki/Metamorphic_rockhttp://en.wikipedia.org/wiki/Eluvial_deposithttp://en.wikipedia.org/wiki/Eluvial_deposithttp://en.wikipedia.org/wiki/Eluvial_deposithttp://en.wikipedia.org/wiki/Sedimentaryhttp://en.wikipedia.org/wiki/Precambrianhttp://en.wikipedia.org/wiki/Indian_Oceanhttp://en.wikipedia.org/wiki/Persian_empirehttp://en.wikipedia.org/wiki/Serendib_(old_name)http://en.wikipedia.org/wiki/Sapphirehttp://en.wikipedia.org/wiki/Berylhttp://en.wikipedia.org/wiki/Ptolemyhttp://en.wikipedia.org/wiki/Gems_of_Sri_Lankahttp://en.wikipedia.org/wiki/Marco_Polohttp://en.wikipedia.org/wiki/Marco_Polohttp://en.wikipedia.org/wiki/Gemstonehttp://en.wikipedia.org/wiki/Sri_Lanka


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Highlightgems in

Sri Lanka


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Sapphir Sapphire is an aluminum oxide. Its colour varies from very light to dark blue to violetish-blue, bluish-green, yellow, slightly reddish-

orange, brown, nearly opaque black, colourless, pink, violet and the pinkish-orange padparadscha (lotus flower)

VarietiesColoured varieties, star sapphire, alexandrite-like sapphire.

SourcesSri Lanka, Kashmir (India), Burma, Thailand, Australia, Tanzania, Kenya, Montana, Madagascar

ToughnessExcellent, except in laminated or fractured stones.

PrecautionsSapphires may fade if heated

HistoryAccording to an ancient Persian legend, the earth rested on a great sapphire whose reflection was seen in the sky. The stonealso appears in the Promethean legend. Prometheus was chained to a rock by Zeus for having stolen fire from the gods.After being rescued by Hercules, a link of the chain remained on his finger, and attached to it was a piece of rock. Zeusagreed to grant Prometheus his freedom if he wore the link as a reminder of his sin. Later a ring set with a sapphire replacedthe link and stone. Sapphire symbolizes truth, sincerity and constancy. It was believed to protect the wearer against captureby an enemy, and to win the favour of princesses. It also protected against poison. It was said that if a poisonous snake wereput in a vessel with a sapphire, the rays from the gem would kill it. The name sapphire originally comes from Sanskrit. Itbecame sappheiros in Greek, meaning blue.


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Ruby Ruby is an aluminum oxide, a variety of corundum; it occurs in medium to dark tones of red and violetish-red to

brownish-red

VarietiesStar ruby

SourcesSri Lanka, Burma, Thailand, Africa (Kenya, Madagascar, Tanzania), India.

ToughnessExcellent, except in laminated or fractured stones.

TreatmentsThe Burmese believed that "blazing red" stones could be found in a "bottomless" valley. Natives threw pieces ofmeat into the valley, hoping that some stones could then be recovered by killing the vultures. In the Royal

Collection of England, you can view a gold ring set with a pale but nearly flawless ruby into which a portrait ofLouis XII of France is carved.

Cuts & UsesFaceted or en cabochon, usually mixed cut (brilliant crown, step-cut pavilion), beads, carved (poor quality).

Choosing a Ruby

The most important factor in the value of a ruby is colour. The top qualities are as red as you can imagine: asaturated pure spectral hue without any overtones of brown or blue. The word red is derived from the Latin word

for ruby, ruber, which is derived from similar words in Persian, Hebrew, and Sanskrit. The intensity of colour of afine ruby is like a glowing coal, probably the most intensely coloured substance our ancestors ever saw. It is nowonder they ascribed magical powers to these fires that burned perpetually and never extinguished themselves.


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Alexandrite Alexandrite is a variety of chrysoberyl, which ideally shows a distinct colour change from green in fluorescent light or

daylight to red in incandescent light.

VarietiesA very small amount of alexandrite shows a cat's eye effect (chatoyancy).

SourcesSri Lanka, Tanzania, Soviet Russia, Brazil, Zimbabwe - Rhodesia, Burma.

ToughnessExcellent

HistoryAlexandrite received its name because it was discovered on the birthday ofCzar Alexander II of Russia in 1830. Red and green are also the colours of the Russian Imperial Guard.

Cuts & UsesAlexandrite is usually faceted. Chrysoberyl cat's eyes must be cut en cabochon to display a chatoyant effect.


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Aquamarine Aquamarine is a blue to greenish-blue or bluish-green variety of beryl.

VarietiesMay occasionally exhibit a cat's eye effect (chatoyancy).

SourcesSri Lanka, Brazil, Madagascar (only historically), Tanzania, Russia, Kenya, Afghanistan, Nigeria.

ToughnessGood

Treatments

Almost all aquamarine is heat-treated to enhance its blue colour. Irradiation with neutron, gamma rays or with x-rays. Colourchange is permanent and is an accepted practice. A morganite (pink beryl) turns deep purple blue (Maxixe type) uponultraviolet irradiation, though the colour is not stable.

HistoryThe word aquamarine comes from the Latin for sea water. In 1910 a 243 lb. crystal was found in Brazil. The outside wasgreenish and the inside was blue. It sold for $25,000 and was cut into many high quality gems. The American Museum ofNatural History has a 13 lb. uncut piece of the green outside portion.


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Cats eye A cat's eye like effect, known as 'chatoyancy', appears to move on this stone's surface. Cat's eye is a gem variety of

chrysoberyl.

Hardness: 8.5 on the Mohs' scale.

DescriptionA translucent variety of chrysoberyl (beryllium aluminum oxide) which exhibits a silvery white line across the stone. Thismoves as the stone, the light source or the observer moves and may appear to open and close like an eye. The finest qualityhas a sharp eye that appears to open and close as the stone is rotated, and exhibits a strong "milk and honey" effect (stoneon one side of the eye appears lighter than the other). These colours switch as the stone or light source is moved. The mosthighly prized body colours are greenish-yellow and brownish-yellow (honey colour).

VarietiesRare specimens also exhibit change of colour.

Sources Sri Lanka, Brazil.

PhenomenaChatoyancy caused by the reflection of light off minute, parallel, needle-like rutile crystals or hollow tubes.


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Peridot Peridot is a silicate of magnesium and iron, occurring in yellowish-green, green, greenish-yellow, brownish-green and brown

(all transparent).

Varieties

Peridot top grades: medium to dark, slightly yellowish-green. Chrysolite ? greenish-yellow, light to dark yellowish-green tobrownish-green to almost brown.

SourcesSri Lanka, Island of Zeberget (Egypt), Burma, USA, Mexico.

ToughnessFair to good

HistoryThe ancients called it the "gem of the sun." They attributed to it the power to dispel enchantment and evil spirits due to it sassociation with the sun (which drives away darkness). In order to be worn as a talisman, it had to be set in gold. The RedSea island of Zeberget, off the southern tip of Egypt, was worked for this stone as early as 1500 B.C. At that time, the islandwas known as "The Island of Serpents," because it was infested with poisonous snakes. Later, the reigning Egyptian king hadthe snakes destroyed to facilitate prospecting for peridot. Prospecting was done at night because the gem could not be seenin sunlight. The workers would mark the spots and return the next day to dig them out.


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GarnetA group of gemstones occurring in every colour but blue. One of earth's most common minerals, though only a small portion is

considered gem quality.

Sources

Rhodolite - Sri Lanka, North Carolina, Tanzania, Kenya, South Africa, Brazil.Almandite - Sri Lanka, India, Brazil, star from Idaho - USA.Pyrope - Czechoslovakia, South Africa, Zimbabwe - Rhodesia, Brazil, Arizona.Grossularite - Sri Lanka, Brazil, Tanzania, Kenya, South Africa, Canada.Andradite - demantoid: Russia, Italy; translucent yellowish or greenish-brown, Arizona.Spessartite - Sri Lanka, Burma, Brazil, Madagascar, Tanzania, Kenya.Uvarovite - Russia, Finland (hardly mined at all).

Toughness

Fair to good

HistorySince earliest times garnets have been carried as amulets against accidents in travel. Asiatic peoples and even our SouthwestIndians used them as bullets, believing that their rich, glowing colour might cause more deadly wounds. The Persians havegiven the garnet a favoured place as a royal stone, allowing it to bear their sovereign's image. Red garnet was once used torelieve fever, yellow garnet to cure jaundice. If the powder failed, the apothecary was accused of using a substitute.

Cuts & Uses

Usually faceted. Sometimes carved into intaglios.


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Amethyts Description

A variety of quartz, silicon dioxide, which appears to be dark purple in transparent light.

VarietiesNone

SourcesSri Lanka, Brazil, Uruguay, Russia, Mexico, Zimbabwe - Rhodesia, Zambia, Arizona.

ToughnessGood

HistoryThe word amethyst comes from the Greek amethustos meaning "not drunk". Therefore, it has been considered acharm against intoxication. A legend accounts for the origin of the stone. Supposedly, Bacchus, the god of wineand conviviality, grew angry at a slight and swore revenge. He decreed that the first mortal to come across his pathwas to be eaten by tigers. Amethyst, a beautiful maiden on her way to worship at the shrine of Diana, happenedto be the victim. Diana , the huntress, changed Amethyst into colourless quartz to protect her from the tigers.


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Topaz Topaz is a fluosilicate of aluminum, occurring in transparent yellow, yellow-brown, orange-brown, light to almost medium

red, very light to light blue, very light green and violet colours.

Varieties

Coloured varieties, Imperial (reddish-orange), chatoyant material (very rare).

SourcesPrime source is Brazil. Sri Lanka (blue), Mexico (mostly poor quality, brownish-yellow), Russia, South Africa (blue), Utah,Afghanistan.

ToughnessPoor, extremely easy basal cleavage - treat with care.

HistoryThe stone began to be used in Marco Polo's time (13th century). Topaz mounted in gold and hung around the neck wasbelieved to dispel enchantment. When the powdered stone was put in wine, it was considered a cure for asthma, insomnia,burns and haemorrhages. Topaz was supposed to become obscure in contact with poison and to quench the heat of boilingwater. All these powers were believed to be increased or decreased with the changes of the moon.Cuts & UsesUsually faceted, often mixed cut due to long prismatic shape of crystal; some stones cut as longish oval or pendeloquestones. The moderately rich colored stones are emerald cut.


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Star stone Star stones of the corundum family are either star sapphires or rubies. When light falls on these stones, a star effect is visible

(known as asterism).

Sri Lanka is the best known source for star sapphires and star rubies. Star sapphires range in colour from grey to bluish-grey

and from medium blue to medium dark blue. The very slightly purplish medium dark blue is the best colour grade for starsapphires. Star rubies range from light pink-red to purple-red through deep purple-red. The intense red star rubies areextremely rare. A good quality star stone should have a high degree of transparency and a well defined star with no weak ormissing rays. It should be reasonably clean and in the face-up position, no distracting inclusions or cracks should be seen.There should be no excess weight at the bottom of the stone.

Star sapphires and rubies are hard stones (9 on the Moh?s scale), which can take a high degree of polish and retain theshinefor a long time. The special optical phenomenon of a well-defined six-ray star is a fascinating sight. The wearablequalities of the star stones make them suitable for men's rings.


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Citrine Description

A transparent variety of quartz, silicon dioxide, occurring in yellow to red-orange to orange-brown. The name is derived fromcitron, which is French for lemon.

VarietiesMadeira (deep, bright reddish-brown) and Palmyra (medium yellowish-brown) are terms used in the trade.

SourcesBrazil, Madagascar, Russia, Sri Lanka.

ToughnessGood

TreatmentsPoor quality amethyst is often heat-treated to achieve a desirable citrine colour.

Cuts & UsesUsually fashioned into ring and pendant stones. The per carat value of cut citrine usually decreases beyond the size of anaverage ring stone.


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Moonstone Moonstones are usually colourless to white, semi-transparent to translucent, and characterised by a glowing light effect

known as adularescence, the visibility of which is confined to a restricted angle of view. The most valuable of the feldspargems.

VarietiesSome may exhibit cat's eye effect.

SourcesSri Lanka, Switzerland, Burma, United States, Madagascar, Tanzania.Phenomena Adularescence- a glowing effect, the finest of which is bluish. Finest quality moonstone is semi-transparent;poorest is translucent. Occasionally a sharp cat's eye may be present.

ToughnessPoor

HistoryConsidered a love charm, moonstone has been attributed the power to arouse tender passions and foretell the future.Therapeutic qualities include protection from lunacy, appeaser of anger and relief from fever.


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Quartz Quartz is the most common mineral on the face of the Earth. Gem varieties include amethyst (purple), citrine (yellow), milky

quartz (cloudy, white variety), rock crystal (clear variety), rose quartz (pink to reddish-pink variety), and smokey quartz(brown to grey variety).

Gem varieties of quartz include: citrine, amethyst, rock crystal, rose quartz, and smokey quartz. There are also varieties ofQuartz cat's eye.

Colours: citrine (yellow); amethyst (purple); rock crystal (colourless); rose quartz (pink); and smokey quartz (purplish-brown).


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Gems in Sri Lanka