Pyrite

Physical Properties

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal Structure: Isometric (often cubic or pyritohedral); Cleavage: Indistinct; Specific Gravity: 4.9-5.2.

Formation & Geological History

Formed in a variety of geological settings including magmatic segregation, hydrothermal veins, and as an authigenic mineral in sedimentary rocks. It is found in rocks of all ages from the Archean to the Holocene.

Uses & Applications

Historically used as a source of sulfur and sulfuric acid. Today it is used in the production of lithium batteries, as a semiconductor material, and as a popular collector's specimen and ornamental stone.

Geological Facts

Known as 'Fool's Gold' because its color and high density lead novice prospectors to mistake it for real gold. It can actually contain small amounts of invisible gold (refractory gold) within its structure.

Field Identification & Locations

Identify by its golden metallic luster and black to greenish-black streak (real gold has a yellow streak). Commonly found in quartz veins, sedimentary coal beds, and metamorphic schists. It is brittle and will shatter if struck, unlike gold which is malleable.

Identified on: 4/30/2026

Mode: Standard