Definition of Opal
1. Noun. A translucent mineral consisting of hydrated silica of variable color; some varieties are used as gemstones.
Definition of Opal
1. n. A mineral consisting, like quartz, of silica, but inferior to quartz in hardness and specific gravity.
Definition of Opal
1. a mineral [n -S]
Medical Definition of Opal
1.
A mineral consisting, like quartz, of silica, but inferior to quartz in hardness and specific gravity.
The precious opal presents a peculiar play of colours of delicate tints, and is highly esteemed as a gem. One kind, with a varied play of colour in a reddish ground, is called the harlequin opal. The fire opal has colours 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.
Origin: L. Opalus: cf. Gr, Skr. Upala a rock, stone, precious stone: cf. F. Opale.
Source: Websters Dictionary
(01 Mar 1998)
Lexicographical Neighbors of Opal
Other Resources:
Arabic