Amphibole
Pronunciation : Am"phi*bole
Part of Speech : n.
Etymology : [Gr. amphibole. Ha?y so named the genus from the great variety of color and composition assumed by the mineral.] (Min.)
Definition : Defn: A common mineral embracing many varieties varying in color and in composition. It occurs in monoclinic crystals; also massive, generally with fibrous or columnar structure. The color varies from white to gray, green, brown, and black. It is a silicate of magnesium and calcium, with usually aluminium and iron. Some common varieties are tremolite, actinolite, asbestus, edenite, hornblende (the last name being also used as a general term for the whole species). Amphibole is a constituent of many crystalline rocks, as syenite, diorite, most varieties of trachyte, etc. See Hornblende.
Source : Webster's Unabridged Dictionary, 1913