mineral

Quartz Pebble (Sea Glass-like Quartz)

Quartz (Silicon Dioxide - SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent; Luster: Vitreous to waxy (when frosted by sand); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to translucent
Luster: Vitreous to waxy (when frosted by sand)

Identified March 27, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal veins or within igneous and metamorphic rocks. This specific specimen has been shaped by 'beach tumble' erosion—mechanically weathered and rounded by wave action and abrasive sand over decades or centuries.

Uses & applications

Common river and beach pebbles are used in landscaping, aquarium decor, and aggregate for concrete. Quality translucent pieces are sometimes collected as 'Cape May Diamonds' or used in lapidary work for tumbled stones.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. When found on beaches, these white rounded stones are often mistaken for sea glass, but their hardness and lack of bubbles distinguish them as natural minerals.

Field identification & locations

Identify in the field by its hardness (cannot be scratched by a steel knife) and its smooth, rounded, frosted surface. Common on coastlines with high silica-content erosion. Collectors look for high clarity or unique 'ghost' inclusions.

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