mineral

Pyrite (likely)

Iron disulfide, FeS₂; commonly called fool’s gold

AI-generated identification · may be incorrect

Brassy yellow, metallic luster, granular/crystalline texture, and uneven fracture; Mohs hardness 6–6.5, specific gravity about 5.0. The specimen appears massive and weathered rather than showing sharp cubic crystals.

Identified August 23, 2026More mineral →

Explore Pyrite (likely) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Forms in reducing environments, especially hydrothermal veins and sedimentary rocks, through sulfide mineral precipitation. Pyrite occurs from Precambrian deposits to modern geological settings.

Uses & applications

Used historically as a sulfur and iron source and occasionally for sulfuric-acid production; attractive crystals are collected, but massive pieces have modest market value. It is not generally used as a gemstone because it tarnishes and can decompose.

Geological facts

Its metallic color resembles gold, but pyrite is harder and more brittle. A streak test gives a greenish-black to brownish-black streak, unlike gold’s yellow streak.

Field identification & locations

Common worldwide, including Spain, Peru, Italy, China, and the U.S.; identify by metallic brass color, high density, brittle fracture, and dark streak. The image is consistent with pyrite, though marcasite or another sulfide cannot be excluded without testing.