mineral

Hematite Nodule

Hematite (Fe2O3)

Hardness: 5.5-6.5; Color: Reddish-brown to steel gray; Luster: Sub-metallic to dull; Crystal structure: Trigonal; Specific gravity: 4.9-5.3; Streak: Cherry red to reddish-brown.

Hardness: 5
Color: Reddish-brown to steel gray
Luster: Sub-metallic to dull

Identified May 17, 2026More mineral →

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Physical properties

Hardness: 5.5-6.5; Color: Reddish-brown to steel gray; Luster: Sub-metallic to dull; Crystal structure: Trigonal; Specific gravity: 4.9-5.3; Streak: Cherry red to reddish-brown.

Formation & geological history

Commonly forms as a result of the precipitation of iron from water. It often occurs in sedimentary environments as a result of chemical precipitation or in metamorphic rocks as a result of hydrothermal activity.

Uses & applications

Primary ore of iron; used in heavy media separation, pigments, jewelry (often as 'black diamonds'), and as a polishing agent (jeweler's rouge).

Geological facts

The name hematite is derived from the Greek word for blood (haima) because of its characteristic red streak. It is responsible for the red color seen in many rocks and even the surface of Mars.

Field identification & locations

Identify by its heavy feel for its size and its distinctive reddish-brown streak when rubbed against an unglazed porcelain plate. Found globally in iron-rich sedimentary deposits like Banded Iron Formations.