Ferruginous Quartz

Physical Properties

Hardness: 7 (Mohs scale), Color: Brownish-red to rusty orange, Luster: Vitreous to dull (due to coating), Crystal Structure: Trigonal/Hexagonal prisms, Specific Gravity: 2.65

Formation & Geological History

Formed through hydrothermal processes where silica-rich fluids crystallize in veins or cavities. The brown/orange tint is caused by iron oxide (Hematite or Limonite) inclusions or surface coatings.

Uses & Applications

Primarily used as collector specimens and in decorative lapidary work. Highly valued by crystal healers and mineral enthusiasts.

Geological Facts

The term 'Ferruginous' comes from the Latin 'ferrum' for iron. These specimens are often found in iron mining districts and are frequently mistaken for smoky quartz, though the color mechanism is chemical rather than radiation-based.

Field Identification & Locations

Identify by its characteristic hexagonal crystal points and the presence of rusty iron staining naturally bonded to the crystals. Commonly found in Morocco, Namibia, and the United States (specifically Arkansas and Arizona).

Identified on: 4/28/2026

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