Ferruginous Quartz (Iron-stained Quartz)

Physical Properties

Hardness: 7 (Mohs scale); Color: Yellow-brown to rusty orange; Luster: Vitreous to earthy (where coated); Crystal Structure: Trigonal (Hexagonal); Cleavage: None (conchoidal fracture).

Formation & Geological History

Formed through hydrothermal processes where silica-rich fluids precipitate into cavities or veins. The yellow-orange color is due to the oxidation of iron-bearing minerals (limonite or hematite) leaching into the quartz matrix.

Uses & Applications

Primary use as a collector's specimen. High-quality varieties are used in lapidary work for cabochons or tumbled stones. Industrially, quartz is used for glass and electronics, though stained quartz is less desirable for these high-purity applications.

Geological Facts

Also known as 'Golden Healer Quartz' in metaphysical circles. The rusty staining can often be removed using weak acids like oxalic acid to reveal the clear or milky white quartz underneath.

Field Identification & Locations

Identify in the field by its high hardness (it will scratch glass/steel) and the distinct crystalline shimmer beneath a thin layer of iron oxide 'rust'. Common in areas with high-silica metamorphic rocks or mining tailings.

Identified on: 4/23/2026

Mode: Standard