mineral

Ferruginous Quartz

Iron-stained Quartz (Silicon Dioxide + Fe2O3 / FeO(OH))

Hardness: 7 (Mohs scale), Color: White to semi-translucent with yellow, orange, and reddish-brown staining, Luster: Vitreous to greasy, Structure: Trigonal/Hexagonal, Cleavage: None/Conchoidal fracture, Specific Gravity: 2.65.

Identified March 4, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes where silica-rich fluids crystallize in veins or cavities. The rust-colored staining occurs when iron-bearing minerals (like hematite or goethite) oxide and seep into micro-fractures in the quartz.

Uses & applications

Primarily for mineral collecting. High-purity quartz is used in electronics and glass-making, though iron impurities often lower industrial value for standard manufacturing.

Geological facts

Also known as 'Limonitic Quartz' or 'Rusty Quartz'. The iron staining can sometimes be removed with oxalic acid to reveal clear or white quartz underneath.

Field identification & locations

Identify by its characteristic quartz hardness (it will scratch glass) and its association with iron-rich soils or gossans. Commonly found in gold-bearing regions as quartz veins often host metallic ores.

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Mineral/Rock

Banded Gneiss (River Rock/Pebble)

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Metamorphic Rock

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