What is opal?

  • (noun): A translucent mineral consisting of hydrated silica of variable color; some varieties are used as gemstones.


Opal is an amorphous form of silica related to quartz, a mineraloid form, not a mineral. 3% to 21% of the total weight is water, but the content is usually between 6% to 10%. It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock, being most commonly found with limonite, sandstone, rhyolite, marl and basalt. Opal is the national gemstone of Australia, which produces 97% of the world's supply. This includes the production of the state of South Australia, which amounts to around 80% of the world's supply.

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Some articles on opal:

List Of Artemis Fowl Characters - S - Gola Schweem
... Schweem indirectly taught Opal Koboi to go into a self-induced coma ... Opal Koboi uses this knowledge to become catatonic for eleven months, while planning the destruction of her enemies ...
Opal, Virginia
... Opal (formerly, Fayettesville) is a census-designated place (CDP) in Fauquier County, Virginia, on U.S ...
Andamooka Opal
... The Andamooka Opal is a famous opal which was presented to Queen Elizabeth II in the 1950s on the occasion of her first visit to Australia ... It was discovered in Andamooka, South Australia, an historic opal mining town ... The opal was cut and polished by John Altmann to a weight of 203 carats (41 g) ...
List Of Marvel Comics Characters: M - Mole
... An employee, Opal Tanaka, discovered him and felt sympathy for him, allowing him to hide there and bringing him food and clothing ... Soon after this, Opal began dating Bobby Drake (Iceman) ... Jealous of Opal's interest in Drake, as well as fearing that Drake may be seeking to harm her, Mole followed the two on their date ...