Yellow Quartz (Citrine or Iron-stained Quartz)

Physical Properties

Hardness: 7 (Mohs scale), Color: Yellow to honey-brown, Luster: Vitreous/glassy, Crystal structure: Hexagonal/Trigonal, Cleavage: None (Conchoidal fracture), Specific Gravity: 2.65

Formation & Geological History

Formed in igneous pegmatites or hydrothermal veins where silicon-rich fluids crystallize. The yellow color is caused by trace amounts of iron or natural irradiation during formation.

Uses & Applications

Commonly used in jewelry, as decorative gemstones, and in metaphysical or mineral collecting. High-grade quartz is also used in the electronics industry for its piezoelectric properties.

Geological Facts

Naturally occurring citrine is quite rare; most commercial 'citrine' is actually heat-treated amethyst. Quartz is the second most abundant mineral in Earth's continental crust.

Field Identification & Locations

Identify in the field by its hardness (will scratch glass and common pocket knives) and lack of cleavage planes. Found globally, prominent sources include Brazil, Madagascar, and the USA.

Identified on: 5/2/2026

Mode: Standard