$Crackle-pattern pyrite cube (Pyrite (iron disulfide, FeS₂), likely a cubic crystal with surface oxidation/fracturing) — mineral$

mineral

Crackle-pattern pyrite cube

Pyrite (iron disulfide, FeS₂), likely a cubic crystal with surface oxidation/fracturing

AI-generated identification · may be incorrect

Brassy yellow metallic luster with black crack-like oxidation lines; pyrite hardness 6–6.5 Mohs, cubic crystal system, no prominent cleavage, and specific gravity about 5.0. The squared shape and metallic appearance are characteristic, though the pattern may be enhanced by weathering or treatment.

Identified September 5, 2026More mineral →

Explore Crackle-pattern pyrite cube 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

Pyrite forms in hydrothermal veins, sedimentary rocks, and metamorphic environments through sulfide mineral precipitation. It ranges from modern formations to specimens millions or billions of years old; the exact age cannot be determined visually.

Uses & applications

Used historically as a sulfur and iron ore and occasionally as a decorative or collector mineral; it is not generally used as a gemstone because it tarnishes and can oxidize.

Geological facts

Often called “fool’s gold,” pyrite is harder and more brittle than gold and commonly produces a dark streak, whereas gold leaves a yellow streak. Oxidation can generate sulfuric acid and damage specimens or surrounding materials.

Field identification & locations

Identify by its brassy color, metallic luster, cubic form, high density, and dark greenish-black streak; do not rely on color alone. Common localities include Spain, Peru, Italy, China, and the United States.