mineral

Milky quartz pebble

Quartz (silicon dioxide, SiO₂)

AI-generated identification · may be incorrect

Typically hardness 7 Mohs, white to translucent, with a vitreous to waxy luster; the specimen appears water-worn and massive rather than crystal-faced. Quartz has a trigonal crystal structure, no cleavage, and conchoidal fracture; specific gravity is about 2.65.

Identified August 11, 2026More mineral →

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Physical properties

Formation & geological history

Likely formed in silica-rich igneous or metamorphic veins and later released by weathering and rounded by stream or beach transport. Quartz formed throughout Earth’s history, so its precise age cannot be determined from the image.

Uses & applications

Common quartz is used in glass, ceramics, abrasives, engineered stone, and electronics; attractive pebbles are sold for landscaping, crafts, and mineral collections.

Geological facts

Its cloudy appearance results from microscopic fluid inclusions, fractures, or dispersed minerals. It may be confused with calcite, but quartz is significantly harder and does not effervesce in dilute hydrochloric acid.

Field identification & locations

Look for glassy luster, irregular conchoidal breaks, and resistance to scratching by steel; a true quartz specimen scratches ordinary glass. Common worldwide, especially in quartz veins and gravel deposits.