mineral

Ferruginous Quartz (Iron-stained Quartz)

Quartz with Iron Oxide inclusions (SiO2 with Fe2O3)

Hardness: 7 on Mohs scale. Color: Orangish-brown, tan, or rusty red due to iron staining. Luster: Vitreous (glassy) to dull. Crystal structure: Trigonal/Hexagonal. Cleavage: Indistinct/Conchoidal fracture. Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Orangish-brown, tan, or rusty red due to iron staining
Luster: Vitreous (glassy) to dull

Identified April 5, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins or as a primary constituent in many igneous and metamorphic rocks. The iron staining occurs when groundwater containing iron minerals (like limonite or hematite) leaches into the cracks of the quartz over thousands of years.

Uses & applications

Used primarily as decorative specimens, in landscaping, and by crystal collectors. High-purity quartz is used in glassmaking and electronics, though stained specimens are usually for aesthetic or local study.

Geological facts

Iron-stained quartz is often mistaken for gold 'ore' or other minerals because of its bright metallic-like orange hue. It is one of the most common mineral varieties found on the Earth's surface.

Field identification & locations

Identify in the field by its hardness (it will scratch glass) and its orange/brown surface coating that does not wash off with water. It is found globally, particularly in areas with high soil acidity or iron content.

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