metamorphic

Graphite-rich metamorphic rock (graphitic schist)

Graphitic schist; chiefly graphite (C), quartz (SiO₂), and mica minerals

AI-generated identification · may be incorrect

Typically dark gray to black with a shiny, greasy-to-metallic luster and flaky foliation; graphite has Mohs hardness 1–2, while quartz and mica raise the bulk-rock hardness to about 3–7. The specimen appears foliated and sparkly, with irregular cleavage along mica-rich layers.

Identified September 2, 2026More metamorphic →

Explore Graphite-rich metamorphic rock (graphitic 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

Formed when carbon-rich shale or organic sediment was subjected to regional metamorphism, commonly during mountain building; ages vary widely from Precambrian to Phanerozoic. Heat and pressure recrystallized organic carbon into graphite and aligned platy minerals.

Uses & applications

Graphite is used in lubricants, refractories, batteries, pencils, and conductive materials; graphitic schist is mainly a teaching or collector specimen and has little construction value.

Geological facts

Graphite is exceptionally soft, electrically conductive, and stable at high temperatures. It can leave a gray-black mark on unglazed ceramic or paper, unlike most dark silicate rocks.

Field identification & locations

Common in metamorphic belts worldwide, including Canada, the United States, Madagascar, Sri Lanka, and China. Field clues are strong foliation, sparkly flakes, a dark streak, and a soapy feel; definitive identification may require a streak or conductivity test.