metamorphic

Quartzite with Milky Quartz Vein

Metamorphosed Quartz-rich Rock (SiO2)

AI-generated identification · may be incorrect

Hardness: 7 (Mohs scale), Color: Gray and milky white, Luster: Vitreous to dull, Crystal structure: Trigonal (microcrystalline), Cleavage: None (conchoidal fracture)

Identified July 10, 2026More metamorphic →

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Physical properties

Hardness: 7 (Mohs scale), Color: Gray and milky white, Luster: Vitreous to dull, Crystal structure: Trigonal (microcrystalline), Cleavage: None (conchoidal fracture)

Formation & geological history

Formed from the metamorphism of quartz sandstone under intense heat and pressure, often during mountain-building events. The white vein suggests secondary quartz precipitation in a fracture.

Uses & applications

Used in construction as road ballast, gravel, and dimension stone; also used in glass manufacturing and as a source of silica.

Geological facts

Quartzite is so tough that it often outlasts the surrounding rock, forming prominent ridges and peaks in mountain ranges.

Field identification & locations

Identify by its extreme hardness (cannot be scratched by steel) and sandy, granular texture that looks like fused sugar crystals. Commonly found in metamorphic belts worldwide.