mineral

Milky Quartz Pebble

Quartz (Silicon Dioxide - SiO2)

Hardness: 7 (Mohs scale); Color: White to translucent waxy; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White to translucent waxy
Luster: Vitreous to greasy

Identified March 7, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White to translucent waxy; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed from the crystallization of molten silica-rich magma or from hydrothermal veins. The rounded shape indicates secondary erosion and transportation by water (alluvial processes) over thousands of years.

Uses & applications

Industrial use for glassmaking and electronics (silicon source); common in construction as aggregate; used in landscaping and tumble-polishing for low-cost jewelry or aquarium decor.

Geological facts

Milky quartz gets its cloudy appearance from minute fluid inclusions of gas or liquid trapped during the crystal's growth. It is one of the most abundant minerals on Earth's crust.

Field identification & locations

Identify in the field by its hardness (it can scratch glass), lack of cleavage, and waxy luster. Commonly found in riverbeds, beaches, and gravel pits across nearly all continents.