mineral

Milky quartz fragment

Quartz (silicon dioxide, SiO₂)

AI-generated identification · may be incorrect

White to translucent, with a vitreous-to-waxy luster and irregular fracture; individual crystals are not clearly visible. Mohs hardness 7, no cleavage, trigonal crystal structure, and specific gravity about 2.65.

Identified September 6, 2026More mineral →

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Physical properties

Formation & geological history

Likely formed when silica-rich fluids crystallized in a vein or cavity within igneous or metamorphic rock. Quartz is common across many geological ages; the specimen’s exact age and source cannot be determined from the photograph.

Uses & applications

Used in glass, ceramics, engineered stone, electronics, and abrasives; attractive pieces are collected, though this small rough fragment has little commercial value.

Geological facts

Milky quartz gets its opacity from microscopic fluid inclusions, fractures, or impurities. It is commonly mistaken for calcite, but quartz is substantially harder and does not effervesce in dilute acid.

Field identification & locations

Common in quartz veins, granite, pegmatite, and metamorphic rocks worldwide. A steel knife should not scratch it; quartz typically scratches glass, while calcite can be scratched easily.