sedimentary

Quartz Breccia with Iron Staining

Tectonic or Sedimentary Breccia (SiO2 with Fe2O3)

Hardness: 7 (Quartz components); Color: White, tan, and reddish-brown; Luster: Vitreous to dull; Structure: Clastic, consisting of angular fragments cemented by a finer matrix; Specific Gravity: ~2.65

Hardness: 7 (Quartz components)
Color: White, tan, and reddish-brown
Luster: Vitreous to dull

Identified July 16, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the mechanical breaking of rocks (brittle deformation) along a fault zone or sedimentary rock collapse, followed by the deposition of iron-rich mineral cements between the angular fragments.

Uses & applications

Primarily collected as geological specimens; occasionally used as decorative stone or crushed for construction aggregate in large-scale operations.

Geological facts

Breccia is distinguished from conglomerate by its angular fragments, which prove the material has not traveled far from its source before being cemented. The red-brown color indicates the oxidation of iron minerals, essentially geological rust.

Field identification & locations

Identify by looking for sharp, angular quartz fragments 'glued' together by a darker, finer-grained matrix. Commonly found near fault lines or in areas with hydrothermal activity.

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