opal
[ oh-puh l ]
/ ˈoʊ pəl /
noun
a mineral, an amorphous form of silica, SiO2 with some water of hydration, found in many varieties and colors, including a form that is milky white.
an iridescent variety of this that is used as a gem.
a gem of this.
Origin of opal
1350–1400; Middle English < Latin
opalus < Greek
opállios opal, gem; probably from a source akin to Sanskrit
upala precious stone
Words nearby opal
opacification,
opacify,
opacity,
opacus,
opah,
opal,
opal glass,
opalesce,
opalescent,
opaleye,
opaline
Definition for opal (2 of 2)
Opal
[ oh-puh l ]
/ ˈoʊ pəl /
noun
a female given name.
Example sentences from the Web for opal
British Dictionary definitions for opal
opal
/ (ˈəʊpəl) /
noun
an amorphous, usually iridescent, mineral that can be of almost any colour, found in igneous rocks and around hot springs. It is used as a gemstone. Composition: hydrated silica. Formula: SiO 2 . n H 2 O
Derived forms of opal
opal-like, adjectiveWord Origin for opal
C16: from Latin
opalus, from Greek
opallios, from Sanskrit
upala precious stone
Scientific definitions for opal
opal
[ ō′pəl ]
A usually transparent mineral consisting of hydrous silica. Opal can occur in almost any color, but it is often pinkish white with a milky or pearly appearance. It typically forms within cracks in igneous rocks, in limestones, and in mineral veins. It also occurs in the silica-rich shells of certain marine organisms. Chemical formula: SiO2·nH2O.