Massive Milky Quartz (with Iron Inclusions)

Physical Properties

Hardness: 7 on Mohs scale; Color: Milky white to yellowish-orange due to iron staining; Luster: Vitreous (glassy) to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & Geological History

Formed from silica-rich hydrothermal fluids cooling in veins or as a late-stage mineral in igneous pegmatites. This specimen likely comes from a vein deposit where iron oxides from groundwater permeated cracks, creating the yellow/orange staining.

Uses & Applications

Used as a flux in smelting, in the manufacturing of glass and ceramics, and as a source of silicon for electronics. Lower quality massive quartz is often used in landscaping or as construction aggregate.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. 'Milky' quartz gets its opacity from millions of microscopic fluid inclusions of gas or liquid trapped during its growth.

Field Identification & Locations

Identify in the field by its hardness (it will scratch glass and steel), lack of cleavage, and waxy/glassy appearance. It is ubiquitous in mountainous terrains and stream beds globally.

Identified on: 4/17/2026

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