mineral
Amethyst-bearing quartz fragment
Quartz, SiO₂, with purple amethyst coloration; likely attached to a green matrix mineral
AI-generated identification · may be incorrectSmall, rough specimen with a purple, translucent crystalline cap and pale green-gray opaque matrix. Quartz hardness is 7 Mohs, vitreous luster, hexagonal crystal structure, and no true cleavage; the green material may be chlorite, epidote, or altered host rock.
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Physical properties
Small, rough specimen with a purple, translucent crystalline cap and pale green-gray opaque matrix. Quartz hardness is 7 Mohs, vitreous luster, hexagonal crystal structure, and no true cleavage; the green material may be chlorite, epidote, or altered host rock.
Formation & geological history
Amethyst forms when iron-bearing quartz crystallizes in silica-rich cavities, commonly in volcanic rocks; irradiation and heat produce the purple color. The specimen’s exact age and matrix cannot be determined from the photograph.
Uses & applications
Used as a gemstone, ornamental stone, and common mineral-collection specimen; this tiny rough piece has little industrial value.
Geological facts
The purple zone appears consistent with amethyst, but image quality prevents confident identification of the green matrix or crystal habit.
Field identification & locations
Look for purple quartz with glassy luster, conchoidal fracture, and hardness sufficient to scratch ordinary glass; verify with a loupe and hardness test on an inconspicuous area. Common sources include Brazil, Uruguay, Mexico, Zambia, and Morocco.
