mineral

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Opaque white to cream/tan; Luster: Vitreous to waxy (especially when water-worn); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Opaque white to cream/tan
Luster: Vitreous to waxy (especially when water-worn)

Identified March 21, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal fluids cooling in veins within the earth's crust. This specific specimen is a 'clast,' meaning it has been detached from its source material and rounded by water erosion over thousands of years in a riverbed or coastal environment.

Uses & applications

Industrial uses include glassmaking, electronics (piezoelectric properties), and abrasives. In jewelry, it is often tumbled or cut into cabochons. It is a staple of beginner rock collecting.

Geological facts

Milky quartz gets its cloudy appearance from microscopic inclusions of gas or liquid trapped during its formation. It is the most common variety of crystalline quartz found on the Earth's surface.

Field identification & locations

Identify in the field by its ability to scratch glass (hardness 7) and its smooth, water-worn texture. It is commonly found in gravel pits, beaches, and creek beds worldwide. Collectors look for pieces with high translucency or unique inclusions.