Milky Quartz

Silicon Dioxide (SiO2)

Rock Type: mineral

Milky Quartz

Physical Properties

Hardness: 7 on Mohs scale; Color: Milk-white to semi-translucent; Luster: Vitreous (glassy) 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 solutions in veins or during the cooling of igneous rocks like granite. Its white color is caused by tiny fluid inclusions of gas and/or liquid trapped during crystal growth.

Uses & Applications

Used in the production of glass, ceramics, and abrasives. High-purity quartz is used in electronics and solar panels. Also popular as a decorative stone and in metaphysical collections.

Geological Facts

Quartz is the most abundant mineral found at Earth's surface. Milky quartz specifically owes its opacity to microscopic bubbles of water or air that were trapped when the crystal formed millions of years ago.

Field Identification & Locations

Identify in the field by its hardness (it will scratch glass), lack of cleavage, and common occurrence in veins. It is found globally, particularly in mountainous regions and riverbeds.

Identified on: 5/6/2026

Mode: Standard