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Usable Gems... and a little opinion.
Play of Color Gems
of color gems are the subject of this month's newsletter, the third in a series on
optical phenomena gems.
of color gems are well named as you can see in the black opal example shown here.
Either of two
optical phenomena can cause certain gems to exhibit a rainbow of colors unrelated
to the gem's own body color... interference and diffraction. This just means that
the color phenomena is caused by something in the gem's structure.
In gemology speak, the colors produced are known as interference
colors or diffraction colors.
A discussion of the way these types of colors are
produced gets somewhat involved. For our purposes lets keep it simple
and talk about the stones that display these
Opal is the best known of the play of color gem
stones. Opal is made up of tiny spheres of silica with minute amounts of water
and air trapped in the spaces among these round spheres.
Light passing through the stone can be broken up into
various colors. The size and arrangement of the silicon spheres influence the
As noted above, the opal shown above is called a black opal... for
reasons. The opal shown here is known as a white opal.
The points of color displayed in opal is known as "fire."
Opal comes in many body colors other than black and
white, including gray, pink, blue, and brown.
displays a type of color play called schiller. The schiller effect is
also seen in other feldspar rocks and gem stones including larvikite
and moonstone. Blue and green effects are most common, but other colors are
Schiller is caused by microscopic thin layers or flakes within
the structure of the stone.
Fire agate is another pretty rock/gem that displays
a play of color phenomena. In this case the phenomena is called iridescence.
is usually caused by thin films of iron oxide or minute internal fractures.
Tucson Gem Shows Are
The world series for colored gem stones is
I think there are more than forty
different gem industry trade shows going on in Tucson over the next couple
This truly is the year's main event
for the gem industry. Dealers and buyers gather in Tucson, Arizona, each
February to meet and greet, swap news, information, speculation, questions and
It's the one time of the year that we can
get together to socialize... and do business.
This is where new discoveries are
introduced to dealers, jewelry manufacturers and retail jewelers.
If you're going to Tucson send me a
note... maybe we can get together.
I hope you noticed our new addition... ads
in the right margin.
It's another small source of revenue for
us (gotta keep those gem prices down) and possibly another resource for you.
We're not sure who will be advertising, since we don't control that. I'm
guessing on-line jewelry sales sites... and maybe even other gem dealers.
I hope the ads will be useful to you.
We'll be adding ads to many of our pages
as we remodel and freshen our web site.
See you in Tucson!
Are you making up heart pendants, stud earrings and other
jewelry for Valentine's Day customers? Now is the time! Talk it up, and
make those sales.