metamorphic

Mica-rich metamorphic rock, likely schist

Biotite–muscovite schist, possibly with quartz and sulfide minerals

AI-generated identification · may be incorrect

Typically Mohs 2–3 for mica and about 7 for quartz; dark gray to silvery, with a shiny micaceous luster and platy, foliated texture. Visible reflective flakes and possible quartz grains indicate layered crystal structure and mica cleavage.

Identified September 16, 2026More metamorphic →

Explore Mica-rich metamorphic rock, likely schist in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Forms when shale or other clay-rich sediment is subjected to regional metamorphism, commonly during mountain building. Its precise geological age cannot be determined from the image; such rocks range from Precambrian to modern orogenic belts.

Uses & applications

Used mainly as a decorative or educational specimen; crushed schist may be used as aggregate or fill, but strong foliation limits structural construction use. Attractive pieces can be collected, though this sample appears ordinary.

Geological facts

The sparkle comes from light reflecting off aligned mica sheets, not necessarily from metallic ore. Rust-colored or brassy grains could indicate iron oxides or pyrite, but they cannot be confirmed visually here.

Field identification & locations

Look for strongly aligned, peelable mica layers, glittery surfaces, and pronounced foliation; a streak, hardness, and acid test would help confirm composition. Common in metamorphic mountain belts worldwide, including the Appalachians, New England, Scotland, and the Alps.