Rock Identifier
Ferruginous Quartz (Iron-stained Quartz (SiO2 with Fe2O3 impurities)) — mineral
mineral

Ferruginous Quartz

Iron-stained Quartz (SiO2 with Fe2O3 impurities)

Hardness: 7 (Mohs scale); Color: Yellow, orange, rusty brown, to dull white; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal (though often massive/river-worn); Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Hardness
7 (Mohs scale)
Color
Yellow, orange, rusty brown, to dull white
Luster
Vitreous to greasy
Identified More mineral

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Physical properties

Hardness: 7 (Mohs scale); Color: Yellow, orange, rusty brown, to dull white; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal (though often massive/river-worn); Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Formation & geological history

Formed through hydrothermal processes or within metamorphic veins. The yellow-brown staining is caused by secondary oxidation of iron-rich minerals (limonite or hematite) that coat the surface or penetrate micro-cracks in the silica.

Uses & applications

Commonly used as a decorative landscaping stone or as a low-value collector specimen. High-quality iron quartz is sometimes used in metaphysical collections.

Geological facts

Also known as 'Limonitic Quartz' or 'Golden Healer' in the gem trade. The iron oxides often create a permanent 'stain' that cannot be washed off without chemical treatment like oxalic acid.

Field identification & locations

Identify in the field by its high hardness (scratches glass), lack of cleavage, and the characteristic rusty orange crust over crystalline silica. Found globally in riverbeds and mountainous terrain.