disthene

Ancient Greek twice + force: compare French disthène. So called in allusion to its unequal hardness in two different directions, or from its positive and negative electric properties.

disthene (plural disthenes)

1. (mineralogy) Kyanite.

• “disthene”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.

• David Barthelmy (1997–2025) “Disthene”, in Webmineral Mineralogy Database.
• “disthene”, in Mindat.org‎^[1], Hudson Institute of Mineralogy, 2000–2025.