Pyrite

Physical Properties

Hardness: 6-6.5; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal System: Isometric (often cubic or framboidal); Fracture: Conchoidal; Streak: Greenish-black; Specific Gravity: 4.9-5.2

Formation & Geological History

Forms in a variety of environments including sedimentary rocks as nodules, in hydrothermal veins, and as an accessory mineral in igneous rocks. This specimen appears framboidal or nodular, likely from a sedimentary context.

Uses & Applications

Historical source of sulfur and sulfuric acid; used in jewelry (as marcasite); used in lithium batteries; collected widely as a mineral specimen.

Geological Facts

Commonly known as 'Fool's Gold' because its color resembles real gold, though it is much harder and more brittle. Sometimes contains trace amounts of real gold within its structure.

Field Identification & Locations

Identify by its metallic luster, golden hue, and high density. Look for its greenish-black streak on a porcelain plate. It is found globally, with notable deposits in Peru, Spain, and the USA.

Identified on: 5/13/2026

Mode: Standard