mineral

Milky quartz (quartz-rich rock fragment)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

White to translucent, vitreous-to-greasy luster with irregular fractures; hardness 7 Mohs, no cleavage, hexagonal crystal structure, and specific gravity about 2.65. The brown areas likely reflect iron-oxide staining or attached host rock.

Identified August 8, 2026More mineral →

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Physical properties

Formation & geological history

Quartz crystallizes from silica-rich hydrothermal fluids, pegmatites, and cooling igneous rocks; this specimen may be a vein-quartz fragment. Its precise geological age and formation locality cannot be determined from the image.

Uses & applications

Common quartz is used in glass, ceramics, foundry materials, abrasives, electronics, and engineered stone; attractive pieces are sold as mineral specimens. It is generally inexpensive unless exceptionally clear, well-crystallized, or from a notable locality.

Geological facts

Milky appearance results from microscopic fluid inclusions, fractures, or tiny mineral impurities scattering light. Quartz is one of Earth’s most abundant minerals and is the defining component of many quartz veins.

Field identification & locations

Identify it by its glassy appearance, lack of cleavage, conchoidal fracture, and ability to scratch ordinary glass; a steel nail will not scratch it. Common sources include hydrothermal veins, granitic pegmatites, and metamorphic terrains worldwide.