Sri Lanka’s gem industry has a very long and colorful history. Sri Lanka was affectionately known as Ratna-Dweepa which means Gem Island. The name is a reflection of its natural wealth. Marco Polo wrote that the island had the best sapphires, topazes, amethysts, and other gems in the world. Ptolemy, the 2nd century astronomer recorded that beryl and sapphire were the mainstay of Sri Lanka’s gem industry. Records from sailors that visited the island states that they brought back “jewels of Serendib”. Serendib was the ancient name given to the island by middle – eastern and Persian traders that crossed the Indian Ocean to trade gems from Sri Lanka to the East during the 4th and 5th century.
Sri Lanka, geologically speaking is an extremely old country. Ninety percent of the rocks of the island are of Precambrian age, 560 million to 2,400 million 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 of gems constitute 90% of the gem deposits in Sri Lanka. Sri Lanka has the highest density of gem deposits compared to its landmass. Ratnapura contains the most gem deposits and derived its name from the gem industry. Ratnapura means “city of gems”.
The blue sapphires from Sri Lanka are known as Ceylon Sapphire. Ceylon Sapphires are reportedly unique in colour, clarity and lustre compared to the blue sapphires from other countries.
Gem trade
The people of the town depends on the gem trade. Gem pits common site in the surrounding area. Most of the large-scale gem businessmen of Sri Lanka operate from Ratnapura. There are considerable numbers of foreign gem traders in town too. Among the foreign traders, Thai (Thailand) traders are in the majority. Every day, large number of traders from suburbs and other towns gather in the town centre to sell or buy gemstones. Large-scale merchants collect gemstones from locals and sell them in the international market. Some traders go out of the city to buy gems. This includes neighboring towns like Kalawana, Bogawantalawa, and Ela-era. After the discovery of world-class alluvial sapphire deposits in the valley of Ilakaka in Madagascar, many Ratnapura merchants travel out of the country to Madagascar to buy gems.
There are over 130 types of minerals
that have been used as gemstones. These include:
- Agate
- Alexandrite and other varieties of chrysoberyl
- Andalusite
- Axinite
- Benitoite
- Aquamarine and other varieties of beryl
- Bixbite (Red beryl)
- Cassiterite
- Chrysocolla
- Chrysoprase
- Clinohumite
- Iolite
- Danburite
- Diamond
- Diopside
- Dioptase
- Dumortierite
- Emerald
- Feldspar (moonstone)
- Garnet
- Hambergite
- Hematite
- Jade – jadeite and nephrite
- Jasper
- Kornerupine
- Kunzite
- Lapis lazuli
- Malachite
- Natural moissanite
- Obsidian
- Olivine (Peridot)
- Opal (Girasol)
- Pyrite
- Quartz and its varieties
- Agate
- Amethyst (cardinal gem)
- Citrine
- Chalcedony (bloodstone)
- Onyx
- Tiger's-eye
- Ruby
- Sapphire dark blue
- Spinel
- Sugilite
- Tanzanite and other varieties of zoisite
- Topaz
- Turquoise
- Tourmaline
- Variscite
- Zeolite (Thomsonite)
- Zircon
Artificial
and synthetic
Artificial or synthetic materials
used as gems include:
- High-lead glass
- Synthetic corundum
- Synthetic cubic zirconia
- Synthetic spinel
- Synthetic moissanite
- Synthetic alexandrite
- Synthetic opal
- Synthetic turquoise
- Synthetic diamond
- Synthetic quartz
- Synthetic beryl
- cristinite
- YAG yttrium aluminum garnet
Organic
There are a number of organic
materials used as gems, including:
- Amber
- Ammolite – from fossils formed from the shells of extinct ammonites.
- Bone
- Coral
- Ivory
- Jet (lignite)
- Nacre (Mother of pearl)
- Pearl
