Mineral

Ferruginous Quartz (Iron-stained Quartz)

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

AI-generated identification · may be incorrect

Hardness: 7 on Mohs scale; Color: Milky white and various shades of reddish-brown; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: Approximately 2.65.

Hardness: 7 on Mohs scale
Color: Milky white and various shades of reddish-brown
Luster: Vitreous to waxy

Identified April 23, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the crystallization of silica in hydrothermal veins or as a secondary mineral in sedimentary environments. The brown coloration is caused by the infiltration of iron oxide (hematite or limonite) into the cracks or crystal lattice during or after formation.

Uses & applications

Common specimens are used primarily for lapidary work (tumbling, cabochons), educational collections, and ornamental decoration. High-quality varieties like Jasper or Carnelian are used in jewelry.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Iron-stained quartz is sometimes mistakenly called 'River Jasper' when it appears as a water-worn river pebble like this specimen.

Field identification & locations

Identify by its hardness (it will scratch glass) and its waxy to glassy appearance despite the surface staining. It is commonly found in riverbeds, gravel pits, and mountain trails worldwide.