mineral

Tumbled amethyst

Amethyst, purple quartz (SiO₂) colored by trace iron and irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; pale lavender to purple, translucent, and typically vitreous, though tumbling gives a smooth satin-to-glossy surface. It has hexagonal quartz structure, no cleavage, and conchoidal fracture; specific gravity is about 2.65.

Identified August 15, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater deposits quartz in gas cavities and fractures of volcanic rocks, especially basalt; purple color develops from iron-related defects. Most commercial material formed in geologically young-to-ancient volcanic provinces, commonly hundreds of millions of years old.

Uses & applications

Used as an inexpensive gemstone, lapidary material, ornamental stone, and meditation/collecting specimen; cut amethyst is also used in jewelry.

Geological facts

The image shows a rounded, polished piece with pale purple quartz and likely internal fractures or inclusions. Color intensity generally increases value, provided the stone is natural and not heat-treated.

Field identification & locations

Identify by its purple color, glassy appearance, hardness, lack of cleavage, and inability to scratch glass easily; common sources include Brazil, Uruguay, Zambia, and Bolivia. A definitive identification may require hardness, refractive-index, or laboratory testing.