There are several good articles on PEARLS in the national Geographic
1. June 1997 Black Pearls (Tahitian)
2. December 1991 Australia's Magnificient Pearls
3. I couldn't find this one but I distinctly remember an article and
video on fresh water pearls (USA south states and Chinese). One
interesting description was how Chinese clams have been induced to
form nacre around a seed of a Buddah figure for making pendants.
Tacky looking but an interesting technique.
While searching my NG collection I found articles on
4. October 1991 Rubies and Sapphires
5. July 1990 The Timeless Mystique of Emeralds
6. September 1987 JADE Stone of Heaven
I am sure if I do a more thorough search there will be more articles
relevant to this group.
The NG articles are all beautifully illustrated and contain original
rarely found in other publication. Perhaps as Jewelers
the Orchid members should make copies of the articles and place them
in file. Colour printers or photocopies are cheap enough to make
colour copies. I have been lurking in this group long enough to
notice that these subjects (gem sources and the working of gems) come
around often and the same misor lack thereof gets
repeated, answers for which have already been clearly addressed in
the NG articles.
Your contention that sophisticated people will always demand
the finest natural gems and that only the "masses" will tolerate the
phonies is , perhaps, going a bit too far. The time is nigh when
discerning between real and synthetic will no longer be feasible,
if, indeed, even relevant. It is now quite feasible to synthesize
natural aberrations so that differentiation is virtually
impossible or, at the very least, economically unfeasible.
I do not work on and know very little about jewelry. But I am a
gadgets guy. Would a hand held battery powered flashlight sized
device- with a UV light source, a laser light*, a halogen light
source to shine through the gem and a nested bank of light filters
for colour, polarized light, a diffraction grating and possibly some
things I haven’t thought of - be a useful tool for a preliminary test
of authenticity. This should eliminate the obvious synthetics or
imitations. For the more expensive gems tests by a certified
gemnologist would be prudent.
*Red lasers, the type used as pointers - Warning, do not look into
the light. The scattering or diffraction of the laser beam passing
through the gemstone should provide some interesting data.
I did some quick tests. A real diamond reflects the laser beam as
multiple focussed points of light, very much like that of the
nightclub mirror ball. Crystal glass lets most of the beam through
with some dispersion and attenuation. Jade lets through the laser, a
dark green portion more easily with less dispersion than the lighter
portions. On another piece of jade the whole piece (a flat ring) the
light scatters evenly throughout the stone, letting little through.
Tests on a quartz capped black opal ring, various small sapphires and
rubies, “jade” were inconclusive but given their under $100 prices
these were bought for their looks not for the value of their stones.
With UV light, stuff that gave a positive were microscopic inclusions
in jade, the jade itself nothing. Tiny rubies on a necklace glowed
red while similar “rubies” in a Siamese Princess ring remained dark.
The black opal glowed blue as did animal ivory and horn.