Quartz (Iron-stained)

Physical Properties

Hardness: 7 on Mohs scale; Color: Milky to translucent with yellow/orange iron staining; Luster: Vitreous; Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & Geological History

Forms in hydrothermal veins or as a primary constituent in igneous rocks like granite. The yellow staining is caused by secondary oxidation of iron-rich minerals (limonite or hematite) leached from surrounding soil or rock.

Uses & Applications

Used widely in glass making, electronics (quartz oscillators), abrasives, and as semi-precious gemstones for jewelry or metaphysical collecting.

Geological Facts

Quartz is one of the most abundant minerals in Earth's crust. Iron-stained quartz is often the first step in the natural formation of 'Citrine,' though natural heat is required for deep internal coloration.

Field Identification & Locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and translucent appearance. Commonly found in riverbeds, mountain outcrops, and inside geodes.

Identified on: 4/28/2026

Mode: Standard