mineral

Polished magnetite-rich stone (probable magnetite or hematite)

Magnetite, Fe₃O₄; possibly hematite, Fe₂O₃

AI-generated identification · may be incorrect

Black to steel-gray, opaque, submetallic to metallic luster, irregularly shaped and polished; magnetite has Mohs hardness 5.5–6.5 and strong magnetism, while hematite is 5–6. Specific gravity is approximately 5.2–5.3.

Identified September 5, 2026More mineral →

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Physical properties

Formation & geological history

Forms chiefly in igneous and metamorphic environments, including iron-rich magmatic segregations, banded iron formations, and hydrothermal veins; many deposits are Precambrian in age, though younger occurrences are widespread.

Uses & applications

Used as iron ore, dense aggregate, pigment, and a natural magnet when strongly magnetic; polished pieces are sold as curios or lapidary specimens.

Geological facts

A magnet strongly attracted to the specimen would favor magnetite; hematite typically leaves a red-brown streak, whereas magnetite leaves a black streak.

Field identification & locations

Common worldwide, especially in banded iron formations and volcanic rocks. Test magnetism, streak color on unglazed porcelain, and heft; the image alone cannot distinguish magnetite from hematite reliably.