mineral

Pyrite Geode

Iron Disulfide (FeS2)

AI-generated identification · may be incorrect

Hardness: 6-6.5 on Mohs scale; Color: Brass-yellow; Luster: Metallic; Crystal Structure: Isometric; Cleavage: Poor; Specific Gravity: 4.9-5.2.

Hardness: 6-6
Color: Brass-yellow
Luster: Metallic

Identified May 3, 2026More mineral →

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Physical properties

Hardness: 6-6.5 on Mohs scale; Color: Brass-yellow; Luster: Metallic; Crystal Structure: Isometric; Cleavage: Poor; Specific Gravity: 4.9-5.2.

Formation & geological history

Formed through hydrothermal precipitation or in sedimentary environments with oxygen-depleted organic material. These specific geodes often form in shale or limestone cavities.

Uses & applications

Primarily used as a minor source of sulfur and iron, in jewelry as marcasite, and as a popular collector's specimen.

Geological facts

Often called 'Fool's Gold' because its color resembles gold, though it is much harder and lacks gold's malleability. Known for forming perfect cubic crystals naturally.

Field identification & locations

Identify by its metallic luster, golden color, and green-black streak on a porcelain plate. Common in locations like Peru, Spain, and the US (e.g., Colorado, Illinois).