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American
gemmological experts have found
that no information has been
traced so far leading to a source
to follow any unusual treatment
process in the Blue Sapphire
treatment techniques in Sri
Lanka.
 This
was revealed by Christopher
P. Smith, Manager Gemological
Research (GIA) at a discussion
held with traders and gemmologists
in Sri Lanka at the Holiday
Inn recently.
The
discussion followed a request
from T. Rusiripala, Chairman,
National Gem and Jewellery Authority
to scientifically prove data
and correct quantitative chemical
analysis of the suspected objects
on a controversial phenomenon
which appeared in "AGTA
Gemstone Update in October 2003,
as revelations based on unverified
sources would lead to tarnish
the image of the industry on
the whole.
Rusiripala
said that in December 2002 the
Be.Lattice diffusion experiments
carried out by American Gemmologists
and Traders Association (AGTA)
had produced certain special
characteristics, which were
rather unusual leading to speculation
that some treatment other than
'simple heating' had taken place.
 This
phenomenon had been described
as a light blue to a near colourless
rim surrounding a deep blue
colour when viewed from different
directions.
The
boundary between the central
blue colour and the outer rim
could be seen to be undulating.
He said that no more sapphires
with this colour distribution
had been observed between December
2002 and June 2003. Again some
more stones with these unusual
characteristics had been found
in June creating doubts among
the traders.
However,
the laboratories involved in
the experiments had stated that
it was inappropriate to speculate
beyond stating that this process
does not appear to be one that
they can recognise as being
"Normal Heat Treatment"
and as no Be has thus far been
found it does not appear to
be a process involving the diffusions
of Be.
The
Chairman said that further laboratory
tests are being carried out
to see how it transpires in
the future and as such no one
should have any doubts on this
matter at present.
Rusiripala
said that according to the norms
in the trade, traders are expected
to divulge the treatment given
to stones and disclose the special
care requirements to the purchaser
and problems arise if they don't
divulge the truth. |
