metamorphic
Schist, likely biotite–muscovite schist
Mica schist; predominantly quartz, feldspar, muscovite and biotite
AI-generated identification · may be incorrectTypically gray to silvery, with a shiny micaceous luster, strong foliation, and platy crystals that split along schistosity; hardness roughly 2–7 depending on mineral grains, specific gravity about 2.6–2.8.
Identified More metamorphic →
Explore Schist, likely biotite–muscovite schist in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Typically gray to silvery, with a shiny micaceous luster, strong foliation, and platy crystals that split along schistosity; hardness roughly 2–7 depending on mineral grains, specific gravity about 2.6–2.8.
Formation & geological history
Formed when shale or another fine-grained sedimentary protolith underwent regional metamorphism under directed pressure, commonly during mountain building; age depends on locality and cannot be determined from the image.
Uses & applications
Used locally as decorative facing stone, landscaping rock, flagstone, and aggregate; attractive mica-rich pieces may be collected, but it is rarely a jewelry material.
Geological facts
The specimen shows coarse, reflective mineral flakes and a strongly layered texture characteristic of schistosity, although the surrounding dark material may be weathered host rock or asphalt-like contamination.
Field identification & locations
Identify it by its visible foliation, glittering mica, and tendency to split into irregular plates; common in metamorphic belts worldwide, including the Appalachians, Alps, Himalayas, and New England. A hand lens and fresh broken surface would improve identification.
More like this
