Milky Quartz
Silicon Dioxide (SiO2)
Rock Type: mineral

Physical Properties
Hardness: 7 on Mohs scale; Color: Opaque white to translucent; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
Formation & Geological History
Formed through the cooling of silica-rich magma or from hydrothermal veins. The milky appearance is caused by microscopic inclusions of fluids or gas trapped during the crystal's growth.
Uses & Applications
Used in glassmaking, abrasives, electronics (piezoelectric properties), various industrial fillers, and as a semi-precious gemstone for carvings or tumbled stones.
Geological Facts
Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz specifically is the most common variety of crystalline quartz found in nature.
Field Identification & Locations
Identify in the field by its hardness (will scratch glass), lack of cleavage, and white, cloudy appearance. It is found globally, often in mountain ranges and riverbeds.
Identified on: 4/23/2026
Mode: Standard