Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Rock Type: mineral

Physical Properties
Hardness: 7 on Mohs scale; Color: White to translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
Formation & Geological History
Formed through the crystallization of silica-rich hydrothermal veins or within pegmatites and igneous rocks. The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth.
Uses & Applications
Used in glassmaking, as an abrasive, in the production of silicon, and widely used in landscaping and as a collector's entry-level mineral.
Geological Facts
Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz is one of the most common varieties, and its cloudiness is due to microscopic fluid inclusions dating back to the mineral's formation.
Field Identification & Locations
Identify by its hardness (it will scratch glass), its lack of cleavage, and its characteristic waxy or glassy luster. Found globally in riverbeds, mountains, and beaches.
Identified on: 5/18/2026
Mode: Standard