Quartzite with Iron Inclusions

Physical Properties

Hardness: 7 on Mohs scale. Color: Tan, brown, white, and yellow bands. Luster: Vitreous to waxy. Crystal Structure: Hexagonal (microcrystalline). Cleavage: None (conchoidal fracture). Specific Gravity: 2.6 - 2.8.

Formation & Geological History

Formed through the metamorphism of quartz sandstone under intense heat and pressure. The distinct coloring is caused by hydrothermal fluids depositing iron oxides into the fractures of the original stone.

Uses & Applications

Commonly used as crushed stone in construction, road ballast, and as a decorative landscaping stone. Tumbled pieces are popular for starting rock collections.

Geological Facts

Quartzite is so hard and chemically resistant that it often outlasts other surrounding rocks during erosion, often forming the peaks of hills and ridges.

Field Identification & Locations

Identify by its ability to scratch glass and its granular, sugary texture where broken. Commonly found in riverbeds or near ancient mountain ranges. Durable and very resistant to weathering.

Identified on: 4/27/2026

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