mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Opaque white to translucent; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (Trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

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

Identified March 23, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Opaque white to translucent; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (Trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Formed from the crystallization of silica-rich hydrothermal solutions in veins or during the cooling of igneous pegmatites. It can be found in rocks of all geological ages, from Precambrian to recent, often occurring as the last mineral to crystallize in a cooling magma body.

Uses & applications

Used as an abrasive in sandpaper, in glass manufacture, as a flux in metallurgy, and in construction as aggregate. Low-grade specimens are common for landscaping, while higher quality pieces are used for lapidary work and metaphysical 'crystals'.

Geological facts

Milky quartz gets its cloudy appearance from microscopic inclusions of fluids (liquid or gas) trapped during the crystal's growth. It is the most common variety of crystalline quartz found on Earth's crust.

Field identification & locations

Identify in the field by its hardness (it will easily scratch glass), its conchoidal (shell-like) fracture, and its white, milky translucency. Commonly found in mountainous regions, riverbeds, and as veins in granite or metamorphic rocks. It is a 'pathfinder' mineral for gold hunters.