Quartz (Iron-stained)

Physical Properties

Hardness: 7 on Mohs scale; Color: Yellowish-brown to tan (due to iron oxide inclusions); Luster: Vitreous/Glassy to waxy; Crystal structure: Trigonal; Cleavage: None (conchoidal fracture).

Formation & Geological History

Formed from silica-rich hydrothermal fluids or within igneous and metamorphic rocks. This specific specimen is river-worn (alluvial), having been rounded by water transport over long periods.

Uses & Applications

Used in glass manufacturing, electronics (piezoelectric properties), abrasives, and as ornamental river stones or lapidary material.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Iron-stained varieties like this are often mistaken for citrine, though the color is usually surface-level or restricted to fractures.

Field Identification & Locations

Identify in the field by its hardness (it will scratch glass) and lack of cleavage. Commonly found in riverbeds, glacial deposits, and mountain outcrops globally. For collectors, look for clarity and unique staining patterns.

Identified on: 4/24/2026

Mode: Standard