Extremely rare, precious opal is in Santa Fe Australian miner discovers valuable gem. Share Copy Link. Copy {copyShortcut} to copy Updated: 8:25 AM MDT May 9, 2013 Alana Grimstad Santa Fe ...

Opals are highly colored, semi-precious stones that form from closely packed silica deposits found in the dry ground of arid regions. TORSTEN BLACKWOOD/AFP/AFP/Getty Images.

Australia produces over 90 percent of the precious opal worldwide, and it's the country's national gemstone. Black opal, ...

Common opal can be found all over the world, but the precious, coloured opal of Lightning Ridge is exceedingly rare. The traditional owners of this land have a longstanding relationship with opal.

Origin: Varied Opal is composed of silica, and it comes in two main varieties: common and precious opals, the latter of which is commonly associated with the month of October, says Woodward.

Australia produces roughly 95% of the world's precious opal supply, and mining is still a popular trade in Coober Pedy. However, most mining is fully mechanized today. Recommended video.

Opal is amorphous, meaning it does not have a defined crystalline shape. ... Australia produces about 95% of the world's precious opal, and it's designated as that country's national gemstone ...

While Mexico, Brazil, Honduras and the United States also have mines, Australia officially claims that "95% of the world's precious opals" come from its territory.

Opal is the traditional birthstone for October.It is believed the stone was discovered in India and given the name "upala," or "precious stone" in Sanskrit, the Geological Institute of America ...

EARLIER work on the structure of opal1 has shown that precious opal, and probably most ‘amorphous’ opals with the notable exception of hyalites, are composed of silica spheres 1500–3000 Å ...