Lanka has been known for thousands of years as a plentiful
source of fabulous gems. Ancient literature from around the
world record the abundance, quality and size of the precious
stones that have originated here and have adorned monarchs
for millennia. The tradition continues. Fine rubies that mined
here have been prized for their size and color. However, in
contemporary times, the sapphires have become more prized
and better associated with Sri Lanka.
International trade in beautiful jewelry has flourished over
the centuries too, continuing to adorn lovers of fine gems
the world over. Traditional methods are still used with tools
that have changed little over the centuries. The spectacular
results however, confirm that modern Sri Lankans are still
just as skilled as their ancestors.
Geological activity many millions of years ago produced metamorphic
rocks carrying gem quality mineral deposits. On the island
of Sri Lanka, such rocks have been exposed at ground surface
due to millions of years of natural weathering and erosion.
Over 90% of the island’s surface is estimated to be
potentially gem-bearing land. Of the five major areas of gem
mining activity in Sri Lanka, Ratnapura (the "City of
Gems"), south-west of the central hills, is the traditional
The gem cutting and finishing industry in Sri Lanka is reputed
to be the fastest developing in the world with the highest
international standards. The jewelry design and manufacturing
trade is also flourishing as skilled artisans practice the
techniques of their ancestors.
Almost the whole island of Sri Lanka consists of Pre-Cambrian
age crystalline rock. There are a few localized sedimentary
deposits close to the north-west coast and at the northern
tip of the island. Small deposits of much younger limestones,
sandstones and mudstones can be found in the north-west and
in the northernmost peninsula.
Geological surveys have shown that the Pre-Cambrian rocks
form three major rock types which were formed by aluminium-rich
sediments collecting in the highland basin existing then.
This mode of genesis has directly resulted in the high prevalence
of aluminium-rich varieties of gem minerals such as corundum,
chrysoberyl, spinel, garnet, beryl, tourmaline and topaz,
etc in these rocks.
All gem mining activity is controlled and supervised by the
National Gem and Jewellery Authority of Sri Lanka. Different
methods of mining are as follows.
1. Open Cast Mining (shallow deposits)
2. Mining by Pits/Shafts and Tunnels
3. Dredging of River Beds – Manual & Gravel Pump