The Gem Island: Sri Lanka’s Precious Stones

Sri Lanka’s gems formed in hot rock hundreds of millions of years ago, then washed into river gravels called illam. Ratnapura, “the city of gems”, leads a mining tradition still based on hand-dug pits. Blue sapphire is the star, but the island yields over 70 gem varieties. Romans, Arabs, Chinese pilgrims and Marco Polo all wrote about its gems. Colour, clarity, cut, carat, origin and treatment shape value, so honest disclosure and lab reports matter. Born in Fire, Carried by Rivers An old Sanskrit name for Sri Lanka is Ratna Dweepa, “island of jewels”. Its Export Development Board counts more than 70 gem varieties here. Every gem has two stories: how it grew deep inside hot rock, and how rivers carried it into the gravels where miners find it. How a sapphire is made Sapphire and ruby are both forms of one mineral, corundum. It is aluminium oxide, and after diamond it is the hardest natural mineral, scoring 9 on…