....purchase some rubybut its treated by filling fissures, would
like opinions and facts on this technique, that is used on various
stones, does it decrease the value?
Lead filled rubies were being sold loose in bins at a recent Tucson
Show for about USD$ 5.00/carat at one of the Chinese vendors booths.
Lead glass filling actually increases the value (for the seller) of
the stones since they would not be able to be sold if they had not
been fracture filled.
Apparently some of the chemicals that Jewelers routinely use in the
shop will eat the lead glass and ruin the appearance of the stones.
what about heat treating stones.. does that also Affect the value?
Tanzanites are all heat treated. If they were not heat treated they
would be Brown and ugly. Heat treatment raises the value of
Aquamarine is usually heat treated " it makes the stones bluer, in
general, and raises their value.
Paraiba Tourmalines from Brasil are almost all heat treated " if
they come out of the heat treatment Neon Blue their value increases
Almost all Citrine on the market is heat treated amethyst. It doesnt
necessarily increase their worth as it takes a nice amethyst to
produce a nice citrine.
Prasiolite is either heat treated amethyst (from specific locations)
or irradiated and heated clear quartz (also from specific
locations). It obviously increases their worth as clear quartz is
basically very inexpensive.
Tourmalines and Yellow Beryl are routinely heated. If dark
tourmalines lighten up, their worth is increased. Yellow beryl is
heated to make the parcels more uniform in color.
Some Rubelites are heated. If they lighten a up and brighten up then
their worth is increased.
All Blue topaz is irradiated and heated. It obviously increases
their worth as clear topaz is basically very inexpensive.
if $30 a ct for fissure filled rubies is a fantastic value
USD$ 5.00 to 10.00 might be a good value $30 a ct seems only to be a
good value for the Seller.
I know they also use this on emeralds as well.
In general the accepted treatment for Emeralds is oiling with a clear
removable oil. Permanently filling Emeralds has not usually been an
accepted practice " except for the Gem-a-Trat (now Excel) people who
have been trying to convince the public that their Permanent method
should be the standard treatment for Emeralds.
Robert P. Lowe Jr.
Lowe Associates - Brasil