Acanthite

Part of speech: noun

Definitions

1. A dark grey silver sulfide mineral that is the stable form of silver at ordinary temperatures and a major ore of silver
2. A naturally occurring mineral composed of silver and sulfur, typically found as dark grey crystals in silver deposits
3. The monoclinic form of silver sulfide, a lustrous grey mineral important as a source of silver metal in mining

Etymology: Acanthite takes its name from a Greek word for "thorn," and the thorn refers to the shape of the crystals rather than anything the mineral does. Under the microscope, acanthite forms sharp, spiky crystals, and when mineralogist James Dana named it in 1855, the thorn-like form was the feature that stood out. The Greek "ákantha" was the word for thorns and spines, and "-ite" is the standard suffix mineralogists attached to mineral names, so the name amounts to "thorny mineral." The word was coined, not inherited. Dana, one of the leading American mineralogists of the nineteenth century, built a name from ordinary Greek parts to describe a mineral he could see was distinctive in its crystal habit. The name has stayed in use since then, and the later standard reference works on the subject continue to record it with this same derivation.

Synonyms: argentite