metamorphic
Amphibolite
Amphibolite, typically composed mainly of hornblende and plagioclase feldspar
AI-generated identification · may be incorrectDark gray-green, coarse to medium-grained and sparkly; commonly Mohs 5–6, with a crystalline texture and no prominent cleavage in the whole rock. The photo suggests an amphibole-rich rock, though exact identification requires examination or testing.
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Physical properties
Dark gray-green, coarse to medium-grained and sparkly; commonly Mohs 5–6, with a crystalline texture and no prominent cleavage in the whole rock. The photo suggests an amphibole-rich rock, though exact identification requires examination or testing.
Formation & geological history
Forms when basaltic or gabbroic rocks undergo medium- to high-grade metamorphism, commonly during mountain building; specimens may range from Precambrian to much younger.
Uses & applications
Used as crushed stone, road aggregate, and sometimes dimension stone; attractive polished pieces are collected or used decoratively.
Geological facts
Amphibolite is a metamorphic rock name defined chiefly by its abundant amphibole minerals, especially hornblende.
Field identification & locations
Look for a dense, dark green-black rock with visible shiny amphibole grains and lighter feldspar; common in metamorphic belts worldwide. A photo alone cannot distinguish it confidently from some other dark metamorphic rocks.
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