opal(redirected from Boulder opal)
Also found in: Thesaurus, Encyclopedia.
1. A mineral of hydrated silica.
2. A gemstone made of this mineral, noted for its rich iridescence.
[Early Modern English, from Middle French opale, from Latin opalus, alteration of Greek opallios, probably from Sanskrit upalaḥ, stone, precious stone (often in the sandhi form opalaḥ in the names of gems such as nīlopalaḥ, sapphire : nīla-, blue + upalaḥ), possibly variant of upara-, lower, from upa, towards, under, down; see upo in the Appendix of Indo-European roots.]
o′pal·ine′ (ō′pə-līn′, -lēn′) adj.
(Minerals) 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: SiO2.nH2O
[C16: from Latin opalus, from Greek opallios, from Sanskrit upala precious stone]
1. a mineral, an amorphous form of silica, SiO2, with some water of hydration, found in many varieties and colors, including milky white.
2. a gemstone made of this, esp. of an iridescent variety.
[1350–1400; Middle English < Latin opalus < Greek opállios opal, gem]
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.
Switch to new thesaurus
|Noun||1.||opal - a translucent mineral consisting of hydrated silica of variable color; some varieties are used as gemstones|
mineral - solid homogeneous inorganic substances occurring in nature having a definite chemical composition
black opal - a dark colored opal with internal reflections of green or red
harlequin opal - a reddish opal with small patches of brilliant color
opaque gem - a gemstone that is opaque
حَجَر عَيْن الشَّمْس: حَجَر كريم
opal[ˈəʊpəl] N → ópalo m
opal[ˈəʊpəl] n → opale f
opal[ˈəʊp/əl] n → opale m or f
a type of usually bluish-white or milky white precious stone, with slight traces or streaks of various other colours. There are three opals in her brooch; (also adjective) an opal necklace. opaal حَجَر عَيْن الشَّمْس: حَجَر كريم опал opala opál(ový) der Opal, Opal-... opal; opal- οπάλιópalo opaal عقیق opaali opaleלשם दूधिया पत्थर opal opál baiduri, opal ópall opale; di opale オパール 단백석, 오팔 opalas opāls opal, baiduri opaalopalopal عقيق opala (de) opal опал opál; opálový opal opal opal โอปอล opal 蛋白石，貓眼石，乳色玻璃 опал دودھيا، ايک پتھر ôpan (khoáng chất) 蛋白石，猫眼石，乳色玻璃