Rock and Mineral Identification Reference

How to Identify Magnetite: Hardness, Streak, Luster and Tests

Quick answer

Magnetite (mineral): 6 identifying properties, 1 home test, and how to tell it from Hematite, quoted from geology department and survey sources.

Updated 2026-09-10 · Sources: University of Minnesota Common Minerals

Scratch, streak and acid tests mark the specimen, and some produce sharp fragments or dust. Wear eye protection, work in a ventilated space, keep acid off skin, and never taste a mineral you have not already identified.

How to Identify Magnetite: Hardness, Streak, Luster and Tests — Photo: Robert M. Lavinsky · CC BY-SA 3.0 · source

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What are the key facts?

Type: Mineral
Mohs hardness: 5.5–6.5 (harder than glass)
Streak: Black
Luster: Metallic to dull luster, opaque.
Color: Black
Cleavage or fracture: No cleavage; brittle.
Specific gravity: 5.2

What Magnetite looks like

The properties that identify Magnetite — mohs hardness: 5.5–6.5 (harder than glass); streak: Black; luster: Metallic to dull luster, opaque; color: Black; cleavage or fracture: No cleavage; brittle; specific gravity: 5.2. Hardness, streak and cleavage are the reliable ones; color alone rarely settles it.

Tests you can do at home

Magnet test: magnetite is the only common mineral that is strongly magnetic — an ordinary magnet will stick to it.

Often confused with

[Hematite](/lookup/rocks-and-minerals/hematite): Streak test: magnetite leaves a black streak; hematite leaves a reddish-brown streak.

Where it is found in North America

Minnesota's Mesabi, Vermilion, and Cuyuna iron ranges, and iron ranges in Wisconsin and Michigan.

How to photograph it for identification

Photograph a fresh, unweathered surface in daylight, then a second shot of any crystal faces or broken edge. Include a coin for scale. If you did a streak test, photograph the streak next to the specimen. The app suggests the likely mineral or rock; confirm with hardness and the tests above before you label it.

FAQ

How hard is Magnetite on the Mohs scale?

5.5–6.5 (harder than glass). A fingernail is about 2.5, a copper coin about 3, a steel knife 5.5 and glass about 5.5, so test against those.

What color streak does Magnetite leave?

Black. Rub the specimen on an unglazed porcelain tile; the powder color is the streak, and it is more consistent than the specimen color.

How do I tell Magnetite from Hematite?

Streak test: magnetite leaves a black streak; hematite leaves a reddish-brown streak.

What is the simplest test for Magnetite?

Magnet test: magnetite is the only common mineral that is strongly magnetic — an ordinary magnet will stick to it.

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Sources

University of Minnesota Common Mineralscommonminerals.esci.umn.edu/minerals-g-m/magnetite
University of Minnesota Common Mineralscommonminerals.esci.umn.edu/minerals-g-m/hematite

Compiled by the RockLens editorial team

Every fact on this page is taken from the sources listed above; numbers and prices are copied from the source, and prices name the guide or auction and its date. Research and drafting were assisted by AI, and each claim was then checked against the cited sources. Checked 2026-09-10. We do not buy, sell or grade items; the app identifies what you photograph and points you to these references.