# How to identify graphite

Canonical page: https://lithomap.app/resources/mineral-identification/graphite
Last reviewed: September 17, 2026
Page purpose: Original LithoMap mineral identification reference for field observations, search systems, and language models.
Classification: Native element · C

## Summary

Graphite is a very soft, opaque form of carbon recognized by its dark gray color, greasy feel, perfect basal cleavage, low density, and black mark on paper or porcelain.

## Quick identification clues

- Mohs hardness about 1 to 2
- Dark gray to black with metallic or earthy luster
- Greasy feel and perfect cleavage in one direction
- Leaves a dark gray to black mark readily

## Composition and classification

Graphite is elemental carbon arranged in stacked sheets. Natural material can contain clay, silicate, sulfide, or other impurities, and carbon-rich rock may contain graphite too fine to identify confidently by eye.

## Appearance

Graphite occurs as platy flakes, scaly masses, earthy material, disseminated grains, and vein fillings. Crystalline flakes are metallic gray and flexible but not elastic.

Fine graphite can make rock look black or silvery and may coat fingers. Weathering and mixed host rock can obscure its characteristic luster and feel.

## Identification tests

- Hardness: About 1 to 2. Scratched very easily by a fingernail.
- Streak or mark: Dark gray to black. Leaves a mark readily, unlike many hard metallic minerals.
- Density: Low; specific gravity about 2.2. Feels light compared with galena or molybdenite.
- Cleavage and feel: Perfect basal cleavage; greasy feel. Supports a layered carbon mineral but should be combined with density and hardness.

## Common lookalikes

- Molybdenite: Much denser, commonly bluish silver, and may leave a greenish-gray rather than black mark.
- Galena: Far denser, brittle, cubically cleaved, and brighter lead-gray.
- Biotite: Forms elastic mica sheets and is harder, with a lighter streak.

## Direct side-by-side comparisons

- Graphite vs. molybdenite — https://lithomap.app/resources/mineral-identification/compare/graphite-vs-molybdenite
- Graphite vs. galena — https://lithomap.app/resources/mineral-identification/compare/graphite-vs-galena

## Most relevant related guides

- Galena — https://lithomap.app/resources/mineral-identification/galena
- Molybdenite — https://lithomap.app/resources/mineral-identification/molybdenite
- Biotite — https://lithomap.app/resources/mineral-identification/biotite
- Diamond — https://lithomap.app/resources/mineral-identification/diamond

## Formation

Much graphite forms when carbon-rich sedimentary material recrystallizes during regional or contact metamorphism.

Graphite also occurs in veins, pegmatites, some igneous rocks, and unusual mantle-derived material. Its texture and host rock help distinguish flake, vein, and amorphous deposit styles.

## Occurrence and geologic setting

Graphite is found in metamorphic belts, carbon-rich schists and gneisses, marbles, veins, and selected igneous settings. Grain size and purity vary widely.

A pencil mark is not proof of graphite in a rock because soot, soft sulfides, and manufactured materials can also mark surfaces.

## Uses and significance

Graphite is used in batteries, refractories, lubricants, foundry products, brake linings, pencils, conductive materials, and specialized high-temperature components.

## Field safety and limitations

- Avoid inhaling fine graphite or mixed mineral dust.
- Do not use electrical conductivity as a casual field test near live circuits.
- Industrial suitability depends on flake size, purity, structure, and processing tests.

## Authoritative sources

- Graphite Statistics and Information — U.S. Geological Survey: https://www.usgs.gov/centers/national-minerals-information-center/graphite-statistics-and-information
- Minerals and their physical properties — U.S. National Park Service: https://www.nps.gov/subjects/geology/minerals.htm
- Mohs Hardness Scale — U.S. National Park Service: https://www.nps.gov/articles/mohs-hardness-scale.htm
- Natural Gemstones: Mineral Gemstones — U.S. Geological Survey: https://pubs.usgs.gov/gip/gemstones/mineral.html

## Specimen photograph

- Image: https://lithomap.app/_delivery/identification/minerals/graphite.webp
- Description: Silvery-gray graphite flakes in marble with white calcite and brown phlogopite
- Creator: Darla Sondrol
- License: CC0 1.0 — https://creativecommons.org/publicdomain/zero/1.0/
- Source record: https://commons.wikimedia.org/wiki/File:Graphite_(GeoDIL_number_-_916).jpg

This reference supports preliminary field identification. It is not a laboratory determination, appraisal, hazard assessment, proof of origin, or statement of land ownership, legal access, or collecting permission.