Image: <bdi><a href="https://www.wikidata.org/wiki/Q126871365" class="extiw" title="d:Q126871365"><span title="photographer from the United States">Shannon Heinle</span></a></bdi> (CC0)
monocliniccommonAmphibole
Hornblende
Na,Ca2(Mg,Fe,Al)5(OH)2(Si,Al)8O22
This sample displays dark, prismatic crystals with a somewhat blocky habit, characteristic of hornblende, and appears to show typical amphibole cleavage.
Hornblende Physical Properties
Mohs Hardness
5Crystal System
monoclinicLuster
vitreousStreak Color
white to light grayCleavage
Perfect in two directions at 56° and 124°Fracture
uneven to conchoidalSpecific Gravity
3Colors
dark green, black, brownTransparency
translucent to opaqueType Locality
NorwayMineral Group
AmphiboleUses
collector, minor industrialAssociated Minerals
feldspar, quartz, biotite, pyroxeneRarity
commonGeological Context
Hornblende is a common rock-forming mineral found in various igneous rocks like granites, diorites, and gabbros, as well as in metamorphic rocks such as amphibolites and gneisses.
