# Graphite vs. galena: how to tell them apart

Canonical page: https://lithomap.app/resources/mineral-identification/compare/graphite-vs-galena
Last reviewed: September 17, 2026
Page purpose: Original LithoMap side-by-side field identification reference for search systems and language models.

## Summary

Graphite and galena can both look metallic gray and leave dark marks. Graphite is soft, greasy, platy, and lightweight; galena is extremely dense, brittle, bright lead-gray, and perfectly cleaved into cubes.

## Bottom line

Heft and cleavage separate them. Lightweight material that marks readily and splits into flakes favors graphite; a very heavy blocky specimen with right-angle cleavage favors galena.

## Side-by-side evidence

- Density: Graphite — Low; specific gravity about 2.2 Galena — Very high; specific gravity about 7.5 Interpretation — Galena is more than three times as dense as graphite.
- Cleavage: Graphite — Perfect in one basal direction, producing flakes Galena — Perfect in three directions at 90°, producing cubes Interpretation — Flaky versus blocky breakage is highly diagnostic.
- Hardness and feel: Graphite — Mohs about 1 to 2; greasy and marks readily Galena — Mohs about 2.5; soft but brittle and not typically greasy Interpretation — Texture and marking behavior reinforce cleavage.
- Color and streak: Graphite — Dark steel-gray to black; dark gray-black mark Galena — Bright lead-gray; gray-black streak Interpretation — These overlap, so color and streak alone are insufficient.

## Field sequence

1. Compare heft before performing any test.
2. Inspect existing breaks for flakes or right-angle cubic steps.
3. Observe whether the surface feels greasy without generating dust.
4. If uncertainty remains, handle the specimen as lead-bearing galena.

## Limits and cautions

- Galena contains lead; avoid dust and wash hands after handling.
- Graphite-rich rock can contain other sulfides, so a dark mark does not certify safety.
- Do not grind, polish, or taste either unknown material.

## Frequently asked questions

### Can graphite look metallic?

Yes. Crystalline graphite commonly has a metallic gray luster despite its low density and softness.

### Do both make a black streak?

Their marks can overlap in color, which is why density and cleavage geometry are more useful.

### Which mineral is heavier?

Galena is dramatically heavier than graphite at equal volume and should feel conspicuously dense.

## Related identification guides

- Graphite: https://lithomap.app/resources/mineral-identification/graphite
- Galena: https://lithomap.app/resources/mineral-identification/galena

## 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
- Lead—Soft and Easy to Cast — U.S. Geological Survey: https://pubs.usgs.gov/publication/fs20113045

This reference supports preliminary field identification. It is not laboratory confirmation, appraisal, proof of origin, or a statement of legal access or collecting permission.