mineral

Tumbled dark metallic mineral specimen, possibly hematite or magnetite

Hematite (Fe₂O₃) or magnetite (Fe₃O₄); visual identification is uncertain

AI-generated identification · may be incorrect

Rounded and polished, dark gray-black with metallic to submetallic luster and granular sparkle. Hematite has Mohs hardness 5–6.5 and reddish-brown streak; magnetite has hardness 5.5–6.5 and a strong magnetic response.

Identified September 21, 2026More mineral →

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At a glance

Common name: Tumbled dark metallic mineral specimen, possibly hematite or magnetite
Scientific name: Hematite (Fe₂O₃) or magnetite (Fe₃O₄); visual identification is uncertain
Category: mineral
Identified: September 21, 2026
Method: Standard

AI Estimated Value

About $2–$15 for a common tumbled piece; attractive crystalline or locality-specific specimens may sell for $20–$100+.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Iron oxides form in hydrothermal veins, igneous rocks, sedimentary iron formations, and weathering environments; specimens may be geologically ancient, though age depends on locality.

Uses & applications

Used as an iron ore, pigment, abrasive, and collector specimen; polished pieces are sometimes sold as ornamental stones or jewelry.

Geological facts

Magnetite is naturally magnetic, while hematite is usually weakly magnetic or nonmagnetic. A streak test is more diagnostic than surface color.

Field identification & locations

Test with a magnet and streak it on unglazed white porcelain: magnetite gives a black streak, hematite a red to reddish-brown streak. The photograph cannot reliably distinguish either mineral from other dark iron-rich stones.