sphene

[ sfeen ]

noun

1. a mineral, calcium titanium silicate, CaTiSiO 5 , occurring as an accessory mineral in a variety of crystalline rocks, usually in small wedge-shaped crystals.

sphene

/ sfiːn /

noun

1. a brown, yellow, green, or grey lustrous mineral consisting of calcium titanium silicate in monoclinic crystalline form. It occurs in metamorphic and acid igneous rocks and is used as a gemstone. Formula: CaTiSiO 5 Also calledtitanite

sphene

/ sfēn /

1. A brown or yellow monoclinic mineral occurring as an accessory mineral in igneous and metamorphic rocks. It usually occurs as wedge or lozenge-shaped crystals. Chemical formula: CaTiSiO 5 .

Word History and Origins

Origin of sphene¹

First recorded in 1805–15, sphene is from the Greek word sphḗn wedge

Word History and Origins

Origin of sphene¹

C19: from French sphène, from Greek sphēn a wedge, alluding to its crystals

Example Sentences

The iron oxides, originally ilmenite, are usually altered to sphene.

From Project Gutenberg

These rocks contain also iron oxides (usually titaniferous), apatite, sometimes sphene, augite and olivine.

From Project Gutenberg

Most gem-stones are harder than quartz, though precious opal, turquoise, moonstone and sphene are inferior to it in hardness.

From Project Gutenberg

Reddish grains of sphene or of garnet are occasionally visible.

From Project Gutenberg

The rarer stones, sphene and epidote, likewise exhibit this property markedly.

From Project Gutenberg