Opal
The opal is a fairly white rock mineral. It is the birthstone for the month of October. Opals are made from tiny spheres of silica (another mineral) and lots of water.
Opal Media
Main opal producing countries
Precious opal consists of spheres of silica molecules arranged in regular, closely packed planes (idealized diagram).
This precious rough opal from Coober Pedy, South Australia, displays nearly every color of the visible spectrum.
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White and blue opal from Slovakia
Brazilian Precious Opal with patches of brilliant color throughout. The brightness of the fire in opal ranges on a scale of 1 to 5 (with 5 being the brightest)
Polished opal from Yowah (Yowah Nut), Queensland
Boulder opal, Carisbrooke Station near Winton, Queensland
Gem grade Ethiopian Welo precious opal pendant
