from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A blue, green or colourless mineral of monoclinic crystals, Fe3(PO4)2·8H2O.
from the GNU version of the Collaborative International Dictionary of English
- n. A hydrous phosphate of iron of a blue to green color, growing darker on exposure. It occurs in monoclinic crystals, also fibrous, massive, and earthy.
from The Century Dictionary and Cyclopedia
- n. In mineralogy, a hydrous phosphate of iron protoxid, occurring crystallized, also cleavable, massive, fibrous, and earthy, nearly colorless when altered, but on exposure becoming blue or green.
Named after its discoverer English mineralogist J. G. Vivian in 1817. (Wiktionary)