mineral

Tumbled quartz (likely citrine or iron-stained quartz)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Mohs hardness 7; pale honey-yellow, translucent, vitreous luster, irregular fracture, and no cleavage. The color may result from iron impurities or heat treatment; crystal structure is trigonal, though this piece is rough/tumbled.

Identified August 20, 2026More mineral →

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Physical properties

Formation & geological history

Quartz forms in igneous, hydrothermal, and metamorphic environments over a wide range of geological ages. Yellow coloration commonly develops from iron-bearing inclusions, natural irradiation, or commercial heat treatment of amethyst.

Uses & applications

Used for ornamental specimens, carvings, and jewelry; quartz is also important industrially in glass, electronics, abrasives, and engineered stone.

Geological facts

True natural citrine is relatively uncommon; much commercial “citrine” is heat-treated amethyst. Quartz can scratch ordinary glass but is not scratched by a steel knife.

Field identification & locations

Look for glassy luster, translucency, hardness, and conchoidal fracture; a streak test should be white. Common sources include Brazil, Madagascar, Uruguay, and the United States, but color alone cannot confirm citrine versus treated quartz.