mineral

Milky Quartz (Tumble Fragment)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White to translucent yellow-white; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 (Mohs scale)
Color: White to translucent yellow-white
Luster: Vitreous to greasy

Identified March 16, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White to translucent yellow-white; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed from the cooling of silica-rich magma or from hydrothermal veins. Often found in pegmatites and metamorphic environments. Geologically ubiquitous, spanning from the Precambrian to present-day mountain-building events.

Uses & applications

Used widely in glassmaking, electronics (piezoelectric properties), abrasives, and as decorative gravel or landscaping stone. Higher quality specimens are used for jewelry or metaphysical collecting.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is clear, but tiny inclusions of fluid or gas cause the 'milky' white or yellowish opacity seen in common field samples.

Field identification & locations

Identify in the field by its hardness (it will scratch glass and cannot be scratched by a steel nail) and lack of cleavage. Commonly found in riverbeds, mountains, and as gravel. Collectors look for well-defined hexagonal crystal terminations.

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