Gemstone mining in Sri Lanka is mostly from secondary deposits.
The gravels yield sapphire,
cat’s-eye, Chrysoberyls, spinel and many other gemstones.
Sri Lanka’s gem-bearing gravels,
called illam, This video showing how to mninig,
traditional heating, traditional cutting process,
the traditional cutting matching call “Hanaporuva”,
and new technology cutting process.
Nature of the world famous Rough gem market in Ratanpura can see this video.