mineral

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: White to semi-translucent/tan
Luster: Vitreous (glassy) to greasy

Identified March 16, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. It is one of the most abundant minerals in the Earth's crust and can be found in virtually all geological environments and ages.

Uses & applications

Used in glassmaking, abrasives, electronics (due to piezoelectric properties), and as a basic gemstone in jewelry or rock tumbling.

Geological facts

Quartz is so chemically and physically stable that it is the primary component of most beach sands. In its pure form, it is clear (Rock Crystal), but inclusions of gas or liquids during formation create the 'milky' appearance seen here.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife and its lack of cleavage planes. Found globally in riverbeds, mountains, and desert environments. Collectors often find these as 'pocket' or 'creek' stones.