Rock Identifier
Heat-Treated Citrine (Amethyst) (Silicon Dioxide (SiO2) with iron impurities) — mineral
mineral

Heat-Treated Citrine (Amethyst)

Silicon Dioxide (SiO2) with iron impurities

Hardness: 7 (Mohs scale), Color: Amber, burnt orange, or brownish-red tips with a white milky base, Luster: Vitreous, Crystal structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified More mineral
Explore Heat-Treated Citrine (Amethyst) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

Physical properties

Hardness: 7 (Mohs scale), Color: Amber, burnt orange, or brownish-red tips with a white milky base, Luster: Vitreous, Crystal structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Formed as amethyst in volcanic geodes (typically in Brazil). The specimens are later artificially heated to high temperatures (approx. 450-550°C) which causes the iron impurities to change color from violet to orange-brown.

Uses & applications

Primarily used as decorative display pieces, in metaphysical collections, and occasionally as lower-cost gemstones for jewelry.

Geological facts

Natural citrine is quite rare and typically pale yellow; the majority of 'citrine' in the commercial market is actually heat-treated amethyst. When heated, the amethyst loses its purple hue and takes on the deep orange color seen here.

Field identification & locations

Identify by looking for a white, opaque base and concentrated dark orange or brownish tips. Natural citrine usually has a more uniform, honey-yellow color throughout the crystal and lacks the stark white base and burnt tips of heated specimens.