mineral
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
Hardness: 7 (Mohs scale), Color: Purple to violet, Luster: Vitreous (glassy), Crystal system: Hexagonal (trigonal), Specific Gravity: 2.65
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Physical properties
Hardness: 7 (Mohs scale), Color: Purple to violet, Luster: Vitreous (glassy), Crystal system: Hexagonal (trigonal), Specific Gravity: 2.65
Formation & geological history
Formed in geodes or hydrothermal veins through the precipitation of silica from mineral-rich fluids, with its purple color resulting from irradiation and iron impurities.
Uses & applications
Secondary stone in jewelry, decorative carvings, metaphysical collections, and historical talismans.
Geological facts
Amethyst was considered a 'Cardinal Gem' until the 18th century, ranked alongside diamonds and rubies in value until large deposits were found in Brazil.
Field identification & locations
Identify by its translucent purple hue and hexagonal crystal habit (if not tumbled). Common in Brazil, Uruguay, and Lake Superior pebble beaches as seen here.
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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