Rock Identifier
Milky Quartz Pebble (Quartz (Silicon Dioxide, SiO2)) — mineral
mineral

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent tan; Luster: Vitreous to waxy; Crystal structure: Trigonal (often massive/rounded in pebbles); Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness
7 on Mohs scale
Color
Milky white to translucent tan
Luster
Vitreous to waxy
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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to translucent tan; Luster: Vitreous to waxy; Crystal structure: Trigonal (often massive/rounded in pebbles); Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed from cooling silica-rich hydrothermal fluids or within igneous and metamorphic rocks. This specific specimen is water-worn, smoothed by erosion in a river or coastal environment over thousands of years.

Uses & applications

Used in construction aggregates, glass making, and filtration. Polished pebbles are used in landscaping and as decorative 'worry stones'.

Geological facts

Quartz is the most abundant mineral on Earth's crust. The 'milky' appearance is caused by tiny inclusions of gas or liquid trapped during the crystal's formation.

Field identification & locations

Identified by its ability to scratch glass, lack of cleavage, and smooth water-worn surface. Found globally in riverbeds, beaches, and soil.

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