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: Poor/indistinct; Specific Gravity: 4.9-5.2.

Formation & Geological History

Forms in a variety of geological environments including sedimentary rocks, hydrothermal veins, and as an accessory mineral in igneous rocks. It forms through the reaction of sulfur with iron-rich minerals in the absence of oxygen.

Uses & Applications

Historically used as a source of sulfur and sulfuric acid. Today, it is used in the manufacture of lithium batteries, as a semiconductor material, and widely collected as a decorative mineral or 'Fool's Gold'.

Geological Facts

Commonly known as 'Fool's Gold' due to its resemblance to precious metal. Historically used in wheel-lock guns to create sparks. It is the most common sulfide mineral on Earth.

Field Identification & Locations

Identify in the field by its brassy color, high hardness (it will scratch glass, unlike real gold), and greenish-black streak when rubbed on a porcelain plate. Common locations include Peru, Spain, Italy, and the USA.

Identified on: 5/15/2026

Mode: Standard