Quartzite Pebble (with Iron Inclusions)

Physical Properties

Hardness: 7 (Mohs scale); Color: White/creamy with orange-brown iron staining; Luster: Vitreous to waxy (smooth surfaces); Crystal Structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.6 - 2.8.

Formation & Geological History

Formed through the metamorphism of quartz sandstone under intense heat and pressure, causing quartz grains to recrystallize and fuse. This specific specimen has been further shaped and polished by water erosion, likely in a river or coastal environment.

Uses & Applications

Used primarily as decorative landscaping stone (river rock), in construction as aggregate, or as an abrasive. Smooth pebbles are also popular for decorative crafts and garden mulch.

Geological Facts

Quartzite is so strong that when it breaks, it breaks through the quartz grains rather than along the boundaries between them. The orange-brown coloring is caused by 'iron staining' or limonite/hematite leaching into microscopic fractures.

Field Identification & Locations

Identify by its ability to scratch glass and its rounded, water-worn texture. It is extremely common in riverbeds and glacial deposits globally. For collectors, look for smoothness and unique patterns caused by internal mineral staining.

Identified on: 4/25/2026

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