mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Opaque white to off-white; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Opaque white to off-white
Luster: Vitreous to greasy

Identified July 1, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Opaque white to off-white; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Forms in hydrothermal veins or as a primary constituent of igneous rocks like granite. This specific specimen has been rounded and smoothed by water transport in a river or coastal environment.

Uses & applications

Used in the production of glass, ceramics, and electronics; also used as landscaping stone, in construction aggregates, and as decorative river rock.

Geological facts

Milky quartz gets its white, opaque appearance from tiny fluid inclusions of gas or liquid trapped during the crystal's growth. It is the most common variety of crystalline quartz on Earth.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), lack of cleavage, and white color. It is extremely common in garden beds, river banks, and gravel pits globally.