Two cleavage directions. Weathering end product(s): Brown clay, limonite. An important rock-forming mineral that occurs in igneous (granite, granodiorite, gabbro) and metamorphic (granite-gneiss, hornblende-schist, greenstone) rocks. Weathers slowly; Gives strength and toughness to rocks. Property values are typical of naturally occurring Hornblende (Iron-Magnesium Silicate). Actual property values will vary from sample to sample. |