Hematite (Tumbled)

Physical Properties

Hardness: 5.5-6.5 on Mohs scale; Color: Steel-gray to black with a metallic luster; Crystal Structure: Trigonal; Cleavage: None; Specific Gravity: 5.26; Streak: Characteristic rust-red/blood-red color.

Formation & Geological History

Formed as a primary mineral and as an alteration product in igneous, metamorphic, and sedimentary rocks. Most major deposits formed as banded iron formations approximately 2.4 billion years ago during the Great Oxygenation Event.

Uses & Applications

Primary ore of iron; used in heavy industry for steel production. In jewelry, it is used for beads, cabochons, and intaglios. Historically used as a pigment (red ochre).

Geological Facts

The name 'hematite' is derived from the Greek word for blood, 'haima', because of the blood-red color of the mineral when ground into powder. NASA's Mars Exploration Rover Opportunity found hematite spherules on Mars, suggesting water once existed there.

Field Identification & Locations

Identify in the field by its high density (feels heavy for its size) and by doing a streak test on unglazed porcelain, which will reveal a red-brown streak. It is common in mining districts and beach sands where iron is present.

Identified on: 4/23/2026

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