mineral

Quartz with Pyrite and Iron Staining

Silicon Dioxide (SiO2) with Iron Disulfide (FeS2) inclusions

Hardness: 7 (Quartz) / 6-6.5 (Pyrite). Color: White milky quartz with metallic brassy pyrite and orange-red iron oxide staining. Luster: Vitreous to greasy for quartz, metallic for pyrite. Crystal structure: Hexagonal (trigonal) for quartz, isometric for pyrite.

Hardness: 7 (Quartz) / 6-6
Luster: Vitreous to greasy for quartz, metallic for pyrite

Identified July 5, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins where mineral-rich hot water circulates through crustal fractures. Pyrite and quartz often crystallize simultaneously from these fluids. The iron staining occurs through the later oxidation of iron-bearing minerals like the pyrite itself.

Uses & applications

Used primarily as decorative garden stone, landscape rock, or as a mineral specimen for collectors. Quartz has massive industrial use in glassmaking and electronics (piezoelectricity), while pyrite was historically a source of sulfur.

Geological facts

Pyrite is famously known as 'Fool's Gold' due to its metallic luster and gold-like color. When quartz shows this white, opaque appearance, it is often called 'Milky Quartz,' caused by microscopic fluid inclusions trapped during the crystal's growth.

Field identification & locations

Identify in the field by the quartz's ability to scratch glass and the pyrite's distinct metallic glint and cubic habit. Common worldwide, especially in mountainous regions with a history of volcanic or tectonic activity. Search near old gold mines or quartz outcroppings.

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