Gemstones & Pearls: News
One of America's finest gems comes to light
When Thomas Ames sat down to carve one of the largest and
finest opals mined from Opal Butte, OR, you can only speculate
about his state of mind. A seasoned glyptic artist, Ames was
about to use his particular technique of sand-blasting a gemstone
masking off strategic areas, blasting, remasking and so
on until the opal yielded to the varying depths and
contours of the Cattleya-laelia orchid design he wanted to create.
But this wasn't a normal opal. First, it was huge over
one pound of rough. It also had an unusual quality. "It
was unlike Australian material, which is opaque and shows its
play of color in reflected light," says Ames. "This
piece had a clarity I've never seen in opal before; I could see
through it, and the fantastic play of color dazzled me."
The opal also has some interesting rounded orange clouds that
some gemologists speculate are concentrations of microscopic
iron oxide stains, similar or identical to the colors seen in
Ames says the opal is of the contra-luz variety, the Spanish
phrase meaning "against the light." The opal composition
(microscopic, tightly packed silica spheres) diffracts reflected
and transmitted light, resulting in red, orange, green, blue
and violet flashes and pinpoints of color. This compostion creates
an ebb and flow to the colors as the gem is rotated and angled
in relation to light.
In addition to the opal's composition, Ames considered its general
outline. "Cut just right," he says, "it has a
rainbow-opal effect." (Rainbow opals typically change body
color entirely, depending on how light is angled in relation
to the gemstones.)
What resulted from Ames' tireless efforts was the 272-ct.
opal carving shown here. The gem won a first-place honor in the
American Gem Trade Association Cutting Edge competition this
year (see Professional Jeweler, October 1999, p. 62).
"It was the largest piece mined at the Blue Mountain
range in Oregon until just last year," says Ames. "Now
a 2-pound piece of pure transparent opal has been cut from the
matrix, though it remains unfashioned."
Almost 2000 years ago, naturalist and philosopher Pliny the
Elder pondered the virtues of opal. He wrote in his epic Natural
History volumes: "There is in them a softer fire than in
the carbuncle [garnet]: there is the brilliant purple of the
amethyst; there is the sea-green of the emerald all shining
together in incredible union."
It's an appropriate salute to Pliny two millennia later. A
singular opal, from a world unknown to him, that perfectly matches
- Thomas Ames, Arvada, CO; (303) 424-3772.
by Robert Weldon, G.G.
||272-ct. opal from Opal Butte, OR, was carved
by Thomas Ames. Photographed with transmitted light, this opal
reveals that it is the contra-luz variety.
Copyright © 1999 by Bond Communications.