mineral

Quartz pebble with host matrix

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to tan with earthy tan matrix; Luster: Vitreous to dull (weathered); Crystal structure: Hexagonal/Trigonal; Conchoidal fracture; Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to tan with earthy tan matrix
Luster: Vitreous to dull (weathered)

Identified June 22, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to tan with earthy tan matrix; Luster: Vitreous to dull (weathered); Crystal structure: Hexagonal/Trigonal; Conchoidal fracture; Specific gravity: 2.65.

Formation & geological history

Formed from silica-rich hydrothermal fluids or cooling magma. This particular specimen is a weathered fragment (pebble) that likely originated from a vein within a host rock and was later rounded by water or environmental erosion.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, and as a common landscaping or decorative stone.

Geological facts

Quartz is one of the most abundant minerals in the Earth's crust and is highly resistant to chemical and physical weathering, which is why it is often found as smooth pebbles long after the host rock has eroded away.

Field identification & locations

Identify in the field by its hardness (will easily scratch glass) and lack of cleavage (it breaks in irregular, shell-like curves). Common in riverbeds, beaches, and mountainous outcrops worldwide.

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Mineral/Rock

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mineral