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)
On the west of the second range we have great masses of kyanite or disthene, and on the flanks of the third and fourth a great deal of specular iron ore which is magnetic, and containing a very large percentage of the metal.