mineral

Milky Quartz (with Iron staining)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to tan/peach (due to hematite/limonite staining); Luster: Vitreous to greasy; Crystal Structure: Trigonal (hexagonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to tan/peach (due to hematite/limonite staining)
Luster: Vitreous to greasy

Identified February 21, 2026More mineral →

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Physical properties

Formation & geological history

Formed from hydrothermal solutions or cooling magma rich in silica. This specimen likely originated in a quartz vein within metamorphic or igneous host rock. Often dates from the Precambrian to Cenozoic depending on the local geology.

Uses & applications

Used in the glass and ceramics industry, as a flux in metallurgy, and as a common gravel for construction. In gemology, it is used for carvings and cabochons. Clearer varieties are used in electronics for piezoelectricity.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. 'Milky' quartz gets its opacity from tiny fluid inclusions of gas or liquid trapped during crystal growth.

Field identification & locations

Identify in the field by its hardness (it will easily scratch glass but cannot be scratched by a steel pocket knife) and its lack of cleavage. Common in riverbeds, mountains, and gardens worldwide. Collectors look for well-defined hexagonal crystal points.

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