Sri Lanka boasts a long history of gemstone production and arguably produces some of the finest gem specimens in the world. Out of the Sri Lankan gemproducing areas, Rathnapura is by far the most prolific source of world-class gemstones. There is a huge variety of gem types found in Sri Lanka and Sapphires are the most popular amongst them. While Rathnapura is well known for its incredible range of gorgeous gems it is also the source of perhaps the finest sapphires in the world. Other cities in Sri Lanka also help expand the range of stones available from this one country with Elahera, Rakwana, Katharagama, Balangoda, Okkampitiya, and Kandy – all providing a source of quality gemstones.
Sri Lanka is also prolific for being amongst the prominent producers of more than 50 varieties of gems which include sapphires. Sri Lanka is one of the most popular and richest countries in gems and stones. It is also known as the “Treasure Box of the Indian Ocean” because of the availability of various kinds of precious gems. Sri Lanka has a renowned center of country’s mining industry stationed at Ratanpura which is popularly known as “The Gem Town”. Sri Lanka as a country has been the prominent supplier of the most precious stones which beautify the crown jewels of various countries like Great Britain and Russia. The list of gemstones produced by the rich lands of Sri Lanka include ruby, sapphire, spinel, the finest chrysoberyl (including cat’s-eye and alexandrite), topaz, tourmaline, quartz, peridot, moonstone, garnet, zircon and a number of other gemstones.
Map of Gem Deposit Areas in Sri Lanka
The Highland Complex of Sri Lanka is the most important area for formation of
gemstone deposits. Illustration by Peter Johnston, © GIA.
(Sri Lanka: From Mine to Market, Part 1, 2014)
A brief breakdown of the popular Gemstones in Sri Lanka
The Ceylon Blue Sapphire is known for its beauty possessing the glorious cornflower blue shade as well as for being one of the few sapphires in the world that can be sold as a completely natural stone without heat treatment. The blues aside, Ceylon sapphires also come in beautiful hues including pink, yellow, orange, green, purple, lavender and of course, the inimitable ‘padparadscha’ sapphire named after the lotus flower. All these highly marketable qualities of Ceylon sapphire has created brand recognition world wide – a brand not created by the producers of the stone, but by the sellers and consumers.
Sapphires that show a star-like light effect are called star sapphires; the most famous star sapphire from Sri Lanka is displayed in the Museum of Natural History in New York. Star sapphires or star rubies display a star-like marking and this effect, commonly known as asterism, occurs when light falls on the cut stone, cut in the cabochon form, and three rays appear giving a six-point star. However, stones with six rays have also been known to occur.
Lastly, there is milky corundum, a white opaque form of corundum also called geuda, which for many years was regarded as useless and discarded, often ending up lining fish tanks in some gemstone merchant’s house. This happened until dealers in Thailand learned to heat-treat geudas to change the colour of the stone from an unattractive cloudy grey-white to a bright, sparkling blue. They completed the work nature began and ended up with a blue sapphire – of much greater value than a useless pebble. The colour of heat-treated blue sapphires are stable and the chemical composition of the stone is that of a sapphire, although prices are lower than for a similar quality stone with natural colour.
Ruby is an aluminum oxide, a variety of corundum; it occurs in medium to dark tones of red and violetish-red to brownish-red.
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.
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 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 shinefor a long.
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.
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 colour, 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.
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 brownishyellow (honey colour).
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).
A variety of quartz, silicon dioxide, which appears to be dark purple in transparent light. This should be cut so that the long portion of the cabochon is 90 degrees to the direction of the needles.
A transparent variety of quartz, silicon dioxide, occurring in yellow to red-orange to orange-brown. The name is derived from citron, which is French for lemon.
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-coloured.
A magnesium aluminum oxide which occurs in all colours, ruby-red being the most popular. Most colours are greyed out. Gahno-spinel is a dark blue or greenish-blue spinel with high zinc content.
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.
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 feldspar gems.
Zircon is a zirconium silicate, occurring in colourless, 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.
Peridot is a silicate of magnesium and iron, occurring in yellowish-green, green, greenish-yellow, brownish-green and brown (all transparent).
Sri Lanka is not just an Island its an Island full of wonders, magnificent gift on earth and an extra ordinarily beautiful country in its natural form. Gems are one of Earth’s best tressures.
And if you are one of those enthusiasts in Gems and beautiful colorful stones, Sri Lanka is your location and we are here to assist you in anything at your convenience. Click on www.bluelankatours.com for more information.
Carol R Taylor