Quartz with Limonite Staining

Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)

Rock Type: Mineral

Quartz with Limonite Staining

Physical Properties

Hardness: 7 (Quartz) and 4-5.5 (Limonite); Color: Grayish-white with yellow-brown staining; Luster: Vitreous to dull; Crystal structure: Trigonal/Amorphous; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65.

Formation & Geological History

Formed in hydrothermal veins or as a secondary alteration product. Limonite staining occurs when iron-bearing minerals oxidize in the presence of water (weathering).

Uses & Applications

Common quartz is used for glassmaking and abrasives. Iron-stained specimens like this are primarily of interest to amateur collectors or as fill material in construction.

Geological Facts

Limonite is not a single mineral but a mixture of hydrated iron oxide minerals like goethite. It often 'paints' quartz crystals a golden or rusty color, which collectors sometimes call 'Golden Healer' in metaphysical circles.

Field Identification & Locations

Identify in the field by checking if the yellow color is a surface coating or internal staining on a hard, glass-like host rock. Commonly found in areas with high iron content and quartz outcroppings.

Identified on: 4/23/2026

Mode: Standard