Item Information

Dimensions (mm) not provided
Weight (carats) not provided

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This is a natural untreated parcel of opal with a blue tone from the oregon opal field that has been drilled.

Weight 13.45 cts app

Size 15 x 11 x 5 mm app

Mohs’ Hardness: 5.5 – 6.5
Density: 1.98 – 2.50
Composition: Hydrous silicon dioxide (SiO2· nH2O)

The opals are found in rhyolite geodes (thundereggs) in a perlite that has altered to a pastel colored clay. The geodes that contain gem-quality opal are only about 10% of the total geodes mined and only about 1% of the geodes contain gem-quality opal with play of color. The remaining geodes contain agate, quartz crystals, or common opal. The geodes vary greatly in size, from a few centimeters in diameter to over a meter.

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$20 gemwiz
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Audit Information

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Pricing & Details

Bid Increment $1
Starting Bid $20
Auction ID 183761
Watchers 11 watching
Viewed 4,471 times
Starts 15th Feb 2023 8:00pm PST
Ends 17th Feb 2023 1:25pm PST

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Volcanicopals Details

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