Mineral

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide inclusions

AI-generated identification · may be incorrect

Hardness: 7 (Mohs scale); Color: Yellow-orange to rusty brown; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Yellow-orange to rusty brown
Luster: Vitreous to greasy

Identified April 12, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Yellow-orange to rusty brown; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed through hydrothermal processes or within igneous pegmatites, where iron-rich groundwater or fluids stained the quartz crystals during or after formation. Common across many geological eras.

Uses & applications

Primarily used as decorative landscaping stone, mineral specimen for collectors, and occasionally as a source of silica in glass manufacturing if found in high purity.

Geological facts

Also known as Hematoid Quartz or Eisenkiesel. The yellow-brown staining is usually caused by Limonite or Goethite (iron oxides) seeping into cracks or being included during crystal growth.

Field identification & locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and the characteristic conchoidal fracture patterns under the orange surface staining. Often found in areas with granite outcrops or gravel pits.