[ noun ] a translucent mineral consisting of hydrated silica of variable color; some varieties are used as gemstones <noun.substance>
Opal \O"pal\, n. [L. opalus: cf. Gr. ?, Skr. upala a rock, stone, precious stone: cf. F. opale.] (Min.) A mineral consisting, like quartz, of silica, but inferior to quartz in hardness and specific gravity.
Note: The {precious opal} presents a peculiar play of colors of delicate tints, and is highly esteemed as a gem. One kind, with a varied play of color in a reddish ground, is called the {harlequin opal}. The {fire opal} has colors like the red and yellow of flame. {Common opal} has a milky appearance. {Menilite} is a brown impure variety, occurring in concretions at Menilmontant, near Paris. Other varieties are {cacholong}, {girasol}, {hyalite}, and {geyserite}.
The normally dry Wilpena Creek became a 12-mile-wide river while the opal mining town of Andamooka in Western Australia state was knee-deep in water.
The stories continued, wild tales of bull hunters and crocodile catchers, crazed opal miners and drunken helicopter musters.
Inside was opal worth hundreds of thousands of dollars.
"I've been married twice, but I never had one before," she said of the ring, an opal set between two diamonds.
She described the ring as having an opal between a pair of diamonds.