Sphene

Part of speech: noun

Definitions

1. A brownish or green mineral made of calcium, titanium and silicate, often valued as a gemstone for its brilliant fire
2. A calcium titanium silicate mineral known for its wedge-shaped crystals and strong dispersion of light, also called titanite
3. Titanite, a silicate mineral of calcium and titanium that forms glassy crystals and is sometimes cut as a gem

Etymology: The mineral sphene owes its name to a crystal's shape. In 1801, the French mineralogist René Just Haüy coined the term "sphène" in his Traité de minéralogie, choosing it for the mineral's distinctive wedge-shaped crystals. He drew on the ancient Greek "sphēn", meaning "wedge", a word that also gave English the "sphenoid" bone of the skull, named for its wedge-like form. The name is a deliberate piece of scientific naming rather than an old folk term. Haüy was one of the founders of modern crystallography, and he often named minerals after the geometry of their crystals, so the word records how the mineral looks rather than where it was found or who first described it. Many mineralogists today prefer the alternative name titanite, which points to the titanium the mineral contains.

Synonyms: titanite