metamorphic
Likely garnet-bearing schist or weathered garnet amphibolite
Garnet (almandine, Fe₃Al₂Si₃O₁₂) in a mica-rich metamorphic matrix
AI-generated identification · may be incorrectDark reddish-brown, earthy to subvitreous luster, visibly foliated and flaky; garnet is Mohs 6.5–7.5, while mica-rich matrix is softer (about 2–3). The specimen appears rough, elongated, and strongly weathered rather than crystalline or gem-quality.
Identified More metamorphic →
Explore Likely garnet-bearing schist or weathered garnet amphibolite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Dark reddish-brown, earthy to subvitreous luster, visibly foliated and flaky; garnet is Mohs 6.5–7.5, while mica-rich matrix is softer (about 2–3). The specimen appears rough, elongated, and strongly weathered rather than crystalline or gem-quality.
Formation & geological history
Formed when clay-rich sedimentary or volcanic protoliths underwent regional metamorphism under elevated temperature and pressure, commonly during mountain building; age cannot be determined from the image and may range from Precambrian to younger.
Uses & applications
Typical material is used chiefly as a teaching or collecting specimen; garnet from some metamorphic rocks is an abrasive, but this fragment has no evident industrial or jewelry value.
Geological facts
Identify it by reddish garnet grains enclosed in aligned mica/hornblende and by its foliation. Common settings include schist belts and metamorphic terranes in India, Madagascar, the Alps, New England, and the western United States.
Field identification & locations
Field confirmation requires a hand lens, streak test, and checking for hard red garnet grains that resist a steel knife; the matrix should split along foliation. The image could also represent a weathered garnet-rich rock or slag-like fragment, so testing is advisable.
More like this
