from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Kyanite.
from the GNU version of the Collaborative International Dictionary of English
- n. Cyanite or kyanite; -- so called in allusion to its unequal hardness in two different directions. See cyanite.
from The Century Dictionary and Cyclopedia
- n. Cyanite: a mineral so called by Haüy on account of its unequal hardness, and because its crystals have the property of being electrified both positively and negatively.
Ancient Greek twice + force: compare French disthène. So called in allusion to its unequal hardness in two different directions. (Wiktionary)