Sri Lanka is one of the world’s most important sources of precious stones, and its gems have long been famous – indeed one of the island’s early names was Ratnadipa, “Island of Gems”. According to legend, it was a Sri Lankan ruby which was given by King Solomon to the Queen of Sheba, while Marco Polo described a fabulous ruby – “about a palm in length and of the thickness of a man’s arm” – set in the spire of the Ruvenveliseya dagoba at Anuradhapura. The island also provided the “Blue Belle” sapphire which now adorns the crown of the British queen, while in 2003 a 478-carat Sri Lankan sapphire – larger than a hen’s egg – fetched $1.5m at auction.
Gems are actually found in many parts of Sri Lanka, but the Ratnapura district is the island’s richest source. The origin of these gems is the geological rubble eroded from the central highlands, which is washed down from the hills along the valleys which crisscross the area – a gravelly mixture of eroded rock, mineral deposits, precious stones and muddy alluvial deposits known as illam. Gem mining is still a low-tech, labour-intensive affair. Pits are dug down into riverbeds and among paddy fields, and piles of illam are fished out, which are then washed and sieved by experts who separate the precious stones from the mud. The mining and sorting is traditionally carried out by the Sinhalese, though gem cutters and dealers tend to be Muslim.
Types of gem
The most valuable precious stones found in Sri Lanka are corundums, a mineral family which includes sapphires and rubies. Sapphires range in colour from blue to as clear as a diamond. Sri Lankan rubies are “pink rubies” (also known as pink sapphires); the better-known red rubies are not found in the island. Garnets, popularly known as the “poor man’s ruby”, and ranging in colour from red to brown, are also found. Cat’s eyes (green to brown) and alexandrite (whose colour changes under different light) are the best known of the chrysoberyl group of stones. Tourmalines are sometimes passed off as the far more valuable cat’s eyes. Other common stones, found in varying hues, are quartz, spinel and zircon. The greyish moonstone (a type of feldspar) is a particular Sri Lankan speciality, though these are not mined in the Ratnapura area. Diamonds and emeralds are not found in Sri Lanka, though aquamarine (like emerald, a member of the beryl family) is.