BLUE OREGON OPAL BEAD 13.45 CTS [VS2162 ]

BLUE OREGON OPAL

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.