Sphenes

Part of speech: noun

Definitions

1. Brownish or green gemstone-quality minerals composed of calcium, titanium, silicon and oxygen, prized for their brilliant fire
2. Wedge-shaped crystals of calcium titanium silicate, also known as titanite, that are valued by collectors for their sparkle
3. Titanite crystals, a silicate mineral with a high dispersion of light that gives them a strong, fiery brilliance when cut

Etymology: "Sphenes" is the plural of "sphene," a mineral name coined in 1801 by the French mineralogist René Just Haüy, who drew on the Ancient Greek word "sphēn," meaning "wedge." Haüy named the mineral for the wedge-like shape of its crystals, which are flattened and angled like the blade of a splitting tool. The word reached English through French "sphène," so it is a scientific coinage rather than an ancient term. Ancient Greeks used "sphēn" for a literal wedge, and the mineral name simply borrowed that old image for a new purpose. Because the plural form refers to more than one specimen or crystal, "sphenes" is the form most often seen in mineralogical writing.

Synonyms: titanite