gemstone

Tumbled amethyst

Amethyst, purple variety of quartz (SiO₂)

AI-generated identification · may be incorrect

Smooth, rounded, translucent-to-opaque deep purple stone with a vitreous luster. Quartz has Mohs hardness 7, a trigonal crystal structure, and no cleavage; the pictured piece appears polished, so its natural crystal faces are absent.

Identified October 4, 2026More gemstone →

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Physical properties

Formation & geological history

Amethyst forms as silica-rich fluids deposit quartz in cavities, commonly in volcanic rocks; its purple color comes from trace iron and natural irradiation. Deposits range from ancient to geologically recent, depending on the host rock.

Uses & applications

Used in jewelry, ornaments, and mineral collections; lower-grade material is also used for decorative objects.

Geological facts

Amethyst is quartz colored by iron-related defects in its crystal lattice. Heat treatment can turn some amethyst yellow or orange, producing citrine-like material.

Field identification & locations

Common sources include Brazil, Uruguay, Zambia, and Madagascar. A purple color and hardness near 7 help identify it; this rounded, uniformly polished appearance indicates tumbling, though a photo cannot confirm the exact material.