Ferruginous Quartz

Physical Properties

Hardness: 7 (Mohs scale); Color: Pinkish-orange to reddish-brown; Luster: Vitreous to waxy; Crystal structure: Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & Geological History

Formed through the crystallization of silica in hydrothermal veins or igneous rocks. The reddish-orange tint comes from iron oxide (hematite or limonite) inclusions or staining that occurred during or after formation.

Uses & Applications

Used primarily as a collector's specimen, in lapidary work for cabochons/carvings, and occasionally in metaphysical practices. Industrially, quartz is used in glass and electronics.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. When iron impurities are within the crystal lattice, it can transition into types like amethyst or citrine, but surface staining or internal inclusions of iron oxide create this specific 'ferruginous' look.

Field Identification & Locations

Identify in the field by its inability to be scratched by a steel knife, its orange staining, and the lack of visible cleavage planes. It is commonly found in riverbeds, glacial deposits, and mountain ranges worldwide.

Identified on: 4/27/2026

Mode: Standard