mineral
Amethyst Quartz
Silicon Dioxide (SiO2) with iron impurities
Hardness: 7 on Mohs scale; Color: Pale violet to deep purple; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
- Hardness
- 7 on Mohs scale
- Color
- Pale violet to deep purple
- Luster
- Vitreous (glassy)
Identified More mineral →
Explore Amethyst Quartz in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 on Mohs scale; Color: Pale violet to deep purple; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
Formation & geological history
Forms in hydrothermal veins and hollow cavities (geodes) within igneous rocks. The purple color is caused by natural irradiation of iron impurities within the quartz crystal lattice.
Uses & applications
Primarily used as a gemstone in jewelry (rings, necklaces), high-end interior decoration, and as a popular specimen for mineral collectors and metaphysical practitioners.
Geological facts
Until the 18th century, amethyst was included in the cardinal gemstones on par with diamonds and rubies. The name comes from the Greek word 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness.
Field identification & locations
Identify by its distinct purple hue and hexagonal prismatic crystal shape terminating in a pyramid. Commonly found in Brazil, Uruguay, and Zambia. In the field, look for volcanic basalt host rocks or vugs.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Nephrite Jade
Nephrite
Mineral/Rock
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety often found as a river rock)
Metamorphic Rock