Semi-precious and precious stones

Srilanka is a major exporter in Semi-precious and precious stones in the world since many centuries. A gemstone is the naturally occurring crystalline form of a mineral, which is desirable for its beauty, valuable in its rarity, and durable enough to be enjoyed for generations. There are more than 30 popular gem varieties and many rarer collector gemstones. Some varieties also come in a range of colors.

The Gem industry in Sri Lanka (also known as Ceylon, Serendib, etc..) has been in existence for over 2500 years. Some of the rarest of gemstones of exquisite beauty have taken pride of place, in the Crown jewels of Kings and Queens from time of Great Roman Emperors.


Gems of Srilanka

Sapphire

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).

Varieties
Coloured varieties, star sapphire, alexandrite-like sapphire. Srilankan blue sapphire is the best in the world and supply gems for the almost all the royal weddings In UK.

History

According to an ancient Persian legend, the earth rested on a great sapphire whose reflection was seen in the sky. The stone also 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. Zeus agreed to grant Prometheus his freedom if he wore the link as a reminder of his sin. Later a ring set with a sapphire replaced the link and stone. Sapphire symbolizes truth, sincerity and constancy. It was believed to protect the wearer against capture by an enemy, and to win the favour of princesses. It also protected against poison. It was said that if a poisonous snake were put in a vessel with a sapphire, the rays from the gem would kill it. The name sapphire originally comes from Sanskrit. It became sappheiros in Greek, meaning blue. Before the value of sapphire was known to them, villages in the Zanzkar mountains of Kashmir (India) used the gem as a flint to start fires.

Cuts & Uses

Faceted and en cabochon, usually mixed cut, beads, carved (poor quality). Synthetic sapphire is used in watches, precision instruments and electronic equipment.

Ruby

STAR RUBY

Ruby is an aluminum oxide, a variety of corundum; it occurs in medium to dark tones of red and violets-red to brownish-red commonly find in Srilanka.
Varieties – Star ruby Toughness -Excellent Cuts & Uses- Faceted or en cabochon, usually mixed cut (brilliant crown, step-cut pavilion), beads, carved (poor quality)

Alexandrite

Alexandrite is a variety of chrysoberyl, which ideally shows a distinct color change from green in fluorescent light or daylight to red in incandescent light and Srilanka is the major supplier in the world.

Varieties – A very small amount of alexandrite shows a cat’s eye effect (chatoyancy). Toughness – Excellent History – Alexandrite received its name because it was discovered on the birthday of Czar Alexander II of Russia in 1830. Red and green are also the colors of the Russian Imperial Guard. Cuts & Uses -Alexandrite is usually faceted. Chrysoberyl cat’s eyes must be cut en cabochon to display a chatoyant effect.

Star stones

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 color from grey to bluish-grey and from medium blue to medium dark blue. The very slightly purplish medium dark blue is the best color grade for star sapphires. Star rubies range from light pink-red to purple-red through deep purple-red. The intense red star rubies are extremely rare. A good quality star stone should have a high degree of transparency and a well-defined star with no weak or missing 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 the shine for a long time. The special optical phenomenon of a well-defined six-ray star is a fascinating sight. The wearable qualities of the star stones make them suitable for men’s rings.

Chrysoberyl

The species name chrysoberyl is given to a transparent, faceted gemstone that does not show a colour change between daylight and artificial light (the chrysoberyl which shows a colour change is called alexandrite). The ideal colours of chrysoberyl are green and yellowish-green. In addition, due to strong dichroism, one may see an attractive bi-coloured chrysoberyl occasionally. Hardness is 8.5 on the Moh’s scale. The high refractive index of the stone makes it very lively when properly cut and polished

CAT”S 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.

There are generally two varieties of cat’s eye. the alexandrite cat’s-eye and the chrysoberyl cat’s-eye, which is very popular in the Far East, particularly in Japan. The ideal colours of the chrysoberyl cat’s-eye are yellowish-brown, which is called the honey color, and the yellow-green, which is called the apple green colour. A very good cat’s eye, apart from being of ideal colour, should have a high degree of transparency and a well-defined unbroken ray. It should be free from any distracting inclusions visible to the unaided eye. The chrysoberyl cat?s-eye is one of the most beautiful gemstones because of the chatoyancy or the eye effect.

Description

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

Varieties- Rare specimens also exhibit change of colour. Sources -Sri Lanka Phenomena – Chatoyancy caused by the reflection of light off minute, parallel, needle-like rutile crystals or hollow tubes.

Toughness – Excellent Miscellaneous- When a gem specimen exhibits both chatoyancy and change of colour, one or both phenomena will suffer. It is more common to find a good eye with poor change of colour. The conditions necessary for one phenomenon conflict with those needed for the other. The term cat’s eye when used alone refers to chrysoberyl. Other minerals exhibiting chatoyancy must be qualified, e.g. tourmaline cat’s eye.
History – Cat’s eye has been regarded as a preserver of good fortune. The natives of Sri Lanka still consider it a charm against evil spirits. British royalty often use it as an engagement stone.

Cuts & Uses- Must be cut in a cabochon to produce cat’s eye effect. This should be cut so that the long portion of the cabochon is 90 degrees to the direction of the needles.

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 of Quartz cat’s eye.

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

Amethyst

Description - A variety of quartz, silicon dioxide, which appears to be dark purple in transparent light. Varieties- None Toughness – Good

History

The word amethyst comes from the Greek amethustos meaning “not drunk”. Therefore, it has been considered a charm against intoxication. A legend accounts for the origin of the stone. Supposedly, Bacchus, the god of wine and conviviality, grew angry at a slight and swore revenge. He decreed that the first mortal to come across his path was to be eaten by tigers. Amethyst, a beautiful maiden on her way to worship at the shrine of Diana, happened to be the victim. Diana, the huntress, changed Amethyst into colourless quartz to protect her from the tigers. When Bacchus witnessed the miracle, he repented and poured wine over the stone, staining it purple. The wine failed to cover the entire stone evenly, and the feet and part of the legs remained clear crystal. So, in keeping with the legend, amethyst crystals are usually uneven in colour with a colourless base. Cuts & Uses -Must be cut in a cabochon to produce cat’s eye effect. This should be cut so that the long portion of the cabochon is 90 degrees to the direction of the needles.

Citrine

Description -A transparent variety of quartz, silicon dioxide, occurs in yellow to red-orange to orange-brown commonly find in Srilanka.. The name is derived from citron, which is French for lemon. Varieties – Madeira (deep, bright reddish-brown) and Palmyra (medium yellowish-brown) are terms used in the trade. Toughness- Good Treatments - Poor quality amethyst is often heat-treated to achieve a desirable citrine color. Cuts & Uses – Usually fashioned into ring and pendant stones. The per carat value of cut citrine usually decreases beyond the size of an average ring stone.

Aquamarine

Aquamarine is a blue to greenish-blue or bluish-green variety of beryl. Varieties- May occasionally exhibit a cat’s eye effect (chatoyancy). Toughness -Good Treatments – Almost all aquamarine is heat-treated to enhance its blue color. Irradiation with neutron, gamma rays or with x-rays. Color change is permanent and is an accepted practice. A morganite (pink beryl) turns deep purple blue (Maxine type) upon ultraviolet irradiation, though the color is not stable. Aquamarine is widely found in Srilanka.

History

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

Cuts & Uses

The step-cut is the most popular because it accentuates the color. As it is often found in large, flawless, even-colored crystals, it is frequently used in pendants and rings. Given a piece of rough with a certain color intensity, the larger stones cut from it will exhibit deeper color.
Other Information Aquamarine is the blue, or perhaps more correctly, blue-green or aqua variety of the mineral beryl. Other gemstone color varieties that belong to beryl include emerald, morganite, and heliodor. Other colors of beryl are simply referred to by their color, such as red beryl. Most gem aquamarines have been heat treated to produce the popular blue-green varieties from less desirable yellow or pale stones.

Garnet

A 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. Species – Rhodolite- violet to purplish-red;

Almandite - red, brownish-red, violetish-red or purple; Pyrope - red; Grossularite – green, yellow, brown, white, colorless, light violet, red, orangey-red; Varieties: hessonite (orange to brown), transparent, green, grossularite. Some show a color change from a mauve-brown to orange-red. Andradite - green, yellow, black. Green called demantoid (high lustre and dispersion); Spessartite - yellow to yellow-brown, dark orangey-brown, reddish-orange, orange; Uvarovite - emerald green, found only in tiny sizes, usually opaque Toughness- Fair to good

History

Since earliest times garnets have been carried as amulets against accidents in travel. Asiatic peoples and even our Southwest Indians used them as bullets, believing that their rich, glowing color might cause more deadly wounds. The Persians have given the garnet a favored place as a royal stone, allowing it to bear their sovereign’s image. Red garnet was once used to relieve 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.

Tourmaline

Tourmaline is a group of minerals comprised of a complex boron-aluminum silicate with one or more of the following: magnesium, sodium, lithium, iron, potassium or other metals. It appears in light from dark red to purple as well as brownish variations of these hues – light to dark green, yellowish-green, greenish-yellow, brownish-orange. It also grows bi-colored.

Varieties- Bi-colored, watermelon, cat’s eye, alexandrite-like (rare) History -Dutch children played with tourmaline because of its ability to attract light objects. The stones were called “aschentrekkers” (ash drawers)

Cuts & Uses – Any cut may be used. Some are carved, some fashioned into beads. Cat’s eye are always cut en cabochon. Sometimes carved to make use of more than one color.Tourmaline is widely find in SriLanka.

Spinel

A magnesium aluminum oxide which occurs in all colors, ruby-red being the most popular in Srilanka. Most colors are greyed out. Gahno-spinel is a dark blue or greenish-blue spinel with high zinc content.

Varieties -Star material is very rare. Toughness- Good

History -

Two of the stones among the Crown Jewels of England are spinels, although they were once thought to be rubies. They are the Black Prince’s Ruby and the Timur Ruby. The 361 carat Timur Ruby is the world’s most famous spinel. Spinel was recognized as a separate species as early as 1587 in Burma Cuts & Uses -Usually faceted.

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 - Colored varieties, Imperial (reddish-orange), chatoyant material (very rare). Toughness - Poor, extremely easy basal cleavage – treat with care.

History

The stone began to be used in Marco Polo’s time (13th century). Topaz mounted in gold and hung around the neck was believed 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 boiling water. All these powers were believed to be increased or decreased with the changes of the moon. Cuts & Uses – Usually faceted, often mixed cut due to long prismatic shape of crystal; some stones cut as longish oval or pendeloque stones. The moderately rich colored stones are emerald cut.

Moonstone

Moonstones are usually colorless to white, semi-transparent to translucent, and characterized by a glowing light effect known as adolescence, the visibility of which is confined to a restricted angle of view. The most valuable of the feldspar gems.Srilanka has the world largest moonstone mine in Mitiyagoda .

Varieties - Some may exhibit cat’s eye effect. 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.

Toughness - Poor

History

Considered 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.

Cuts & Uses - Usually en cabochon, sometimes carved into cameos. Generally used as an inexpensive stone for rings, pendants, etc.

Zircon

Zircon is a zirconium silicate, occurring in colorless, light blue, brownish-orange, yellow, yellowish-green, brownish-green, dark red or light red-violet. Blue is the most valuable. This stone is usually heat-treated. Varieties -High, medium and low property. Precautions -Avoid heat. Boiling and steaming not recommended.

History

The terms hyacinth or jacinth were often applied to the reddish-brown zircon. During the Middle Ages, hyacinth was claimed to have the power of inducing sleep, of promoting riches, honor and wisdom and of driving away plagues and evil spirits. The pale yellow to colorless stones from Ceylon (Sri Lanka) were called jargoons.

Cuts & Uses- The round brilliant cut is most successful, standard 57-facets with no culet.

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 to brownish-green to almost brown.

Sources

Sri Lanka, Island of Zeberget (Egypt), Burma, USA, Mexico. Toughness- Fair to good

History

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

Cuts & Uses

Usually faceted. Step-cut is best; oval, round and pendeloque cuts are common. Very suitable for brooches, pendants, earrings, but not for rings or bracelets because it abrades easily.

Blue Giant of the Orient (466 carats)

At 486.52 carats, this gem is considered to be the largest blue sapphire in the world. Discovered in Sri Lanka in 1907, the gem was sold to an anonymous American collector and connoisseur of gemstones and art works. Nothing was heard of the stone until 2004, when the “Blue Giant of the Orient suddenly appeared at a Christie’s Magnificent Jewels sale held on May 19, 2004 in Geneva, Switzerland.

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Star of India (563 carats)

This gemstone is a 563.35-carat grayish-blue star sapphire discovered in Sri Lanka. J.P. Morgan donated the Star of India to the American Museum of Natural History in New York in 1900.

Logan Blue Sapphire (423 carats)

The Logan is a 423-carat rich deep blue sapphire that was discovered in Sri Lanka. The gem has been set in a brooch and surrounded by twenty round brilliant-cut diamonds. The gem has been named in honor of Mrs. John A. Logan. She donated the stone to the Smithsonian National Museum of Natural History in Washington, D.C. in 1960.

Star of Lanka (362 carats)

Third largest star sapphire on the record. The phenomenal stone is a rich deep blue in color and has a well-defined six-ray star. Owned by the National Gem & Jewellery Authority in Sri Lanka.

Rosser Reeves Star Ruby (138 carats)

At 138.7, the Rosser Reeves Star Ruby is one of the world’s largest and finest star rubies. This Sri Lankan stone is renowned for is fantastic color and well defined star pattern. Advertising mogul Rosser Reeves donated the piece to the Smithsonian National Museum of Natural History in Washington, D.C. in 1965.

Ray of Treasure (103 carats)

The Ray of Treasure is a 103-carat chrysoberyl cat’s eye discovered in Sri Lanka. This gemstone is a fine example of the most desirable qualities of cat’s eye stones. It is currently part of the collection of the National Gem and Jewelry Authority (NGJA) in Sri Lanka.