mineral

Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite/Goethite inclusions

Hardness: 7 (Mohs scale); Color: Rusty orange, reddish-brown, or yellow-tan; Luster: Vitreous to earthy (if heavily coated); Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65-2.73.

Hardness: 7 (Mohs scale)
Color: Rusty orange, reddish-brown, or yellow-tan
Luster: Vitreous to earthy (if heavily coated)

Identified March 7, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes where quartz crystals precipitate from silica-rich fluids. The distinct orange-red coloration comes from the later infiltration of iron oxides (hematite or limonite) into micro-cracks or as a surface coating during weathering in iron-rich soils.

Uses & applications

Commonly used as decorative garden stones, in metaphysical crystal collections (often sold as 'Tangerine Quartz'), and occasionally as a minor local construction aggregate or road base when found in abundance.

Geological facts

Also known as 'Hematoid Quartz' or 'Ferruginous Quartz,' the name comes from the Latin 'ferrum' for iron. Because quartz is highly resistant to chemical weathering, these specimens often survive as gravels in riverbeds long after their parent rock has eroded.

Field identification & locations

Identify in the field by its high hardness (it will scratch glass) and its orange-brown staining that cannot be easily washed off with water (unlike common mud). Usually found in areas with iron-rich soil or near hydrothermal vein deposits.

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