Milky Quartz

Silicon Dioxide (SiO2)

Rock Type: mineral

Milky Quartz

Physical Properties

Hardness: 7 (Mohs scale); Color: White to creamy white; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65.

Formation & Geological History

Forms through the crystallization of magma or from hydrothermal veins. Milky quartz specifically gets its appearance from tiny fluid inclusions of gas or liquid trapped during crystal growth. It is found in many geological environments ranging from Precambrian to recent ages.

Uses & Applications

Used as an abrasive in sandblasting, in the manufacture of glass and ceramics, as a gemstone (tumbled or cabochon), and in gravel for landscaping and construction.

Geological Facts

Milky Quartz is the most common variety of crystalline quartz. While clear quartz is prized for clarity, the milky variety is historically significant as a source of gold in 'mother lode' vein deposits.

Field Identification & Locations

Identify by its white color, ability to scratch glass (hardness 7), and lack of cleavage. It is found globally in riverbeds, mountains, and soil. Collectors should look for unique shapes or associations with other minerals like tourmaline.

Identified on: 5/4/2026

Mode: Standard