Sapphire Rush in Kataragama - National Gem & Jewellery Authority

no gravel has been discovered so
far. The overburden is rather thick as
a result of weathered gniesses and
marble.
The production so far has not
been encouraging, the miners said.
They, however, believe that they will
hit a gem vein in the near future.
The authors have observed
faceted stones weighing up to 15
carats and well-formed crystals
of up to 5cm. Most of the crystals
contain numerous mineral inclusions,
which are being researched for their
identity.
There has been speculation about
the origin of these sapphires. Since
there is no gem gravel (illam), an
alluvial origin cannot be considered.
A pegmatite origin is not logical
since there is no evidence pointing
to typical pegmatitic accessory
minerals. The presence of various
micas is not evident too.
This area had been excavated in search of gem gravel. (Photo: Gamini Zoysa)
It could not be an alluvial gem
deposit similar to the contemporary
mines in Ratnapura or Elahera in Sri
Lanka. In our opinion, the crystals have not
traveled any distance from their original
source. It might be worth considering it as
an eluvial gem deposit.
Acknowledgement:
The authors wish to thank Mr. Nimal Bandara,
director general of the National Gem & Jewelry
Authority (NGJA), and Mr. S. Edirisingha, NGJA’s
chief valuer, for facilitating their visit to the mines
and providing them with relevant statistics.
Jewelers Ethics Assoc InColor19_HPH.indd 1 24/04/2012 1:35 PM
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