mineral

Milky quartz (quartz-rich rock fragment)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

White to translucent, vitreous-to-waxy luster, irregular fracture with possible conchoidal surfaces; Mohs hardness 7, no cleavage, hexagonal crystal structure, specific gravity about 2.65. The brown staining is likely iron-oxide coating or inclusions.

Identified August 16, 2026More mineral →

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Physical properties

Formation & geological history

Quartz crystallizes from silica-rich hydrothermal fluids, igneous melts, or metamorphic veins; this specimen may be vein quartz weathered from host rock. Quartz commonly formed throughout Earth’s geologic history, including Precambrian and younger rocks.

Uses & applications

Used in glass, ceramics, engineered stone, electronics, abrasives, and construction aggregate; attractive translucent pieces are collected or polished. This rough fragment has modest commercial value.

Geological facts

Quartz is among Earth’s most abundant minerals and is piezoelectric, producing an electrical charge when mechanically stressed.

Field identification & locations

Identify by its hardness— it should scratch ordinary glass—lack of cleavage, and pale translucent appearance. Common worldwide, especially in quartz veins and granitic or metamorphic terrains; value is typically $1–$10 for a common rough piece, or $10–$30 if unusually clear or attractive.