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CHRYSOPRASE ROUGH
There's a lot of grinding
and sawing to gem rough before it's ready for either cabbing or facetting. |
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CHRYSOPRASE PREFORMS
The pieces here are ready to
be shaped into preforms. Preforms are very basic cubes, rounds,
ovals, triangles or rectangles. The yield from cabbing material in
this stage is around 30%. The yield from facetting material in this
stage is around 20%. It's important that the preforms are clean and
free from inclusions.
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MARLBOROUGH CHRYSOPRASE
This rough traveled from the
mine to Hong Kong in the late eighties. There it sat in a warehouse.
Next it came to Arizona in the early 2000's. A small amount of it
comes to the Tucson Gem and Mineral show every year. We buy it.
Bring it to the lapidary in San Francisco, rough it out, and send it off
to Hong Kong for finishing. Or something like that! It's not
too unusual a story for gemstones these days. |
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MARLBOROUGH CHRYSOPRASE
This 3800g chunk has around
800 gm of trim, 2000 gms of included material, and optimistically 1000 gm
of clean cutting material. Or maybe only 500 gms of clean cutting
material, sigh... pretty though, isn't it?
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