mineral
Amethyst and Calcite collection
Silicon Dioxide (SiO2) and Calcium Carbonate (CaCO3)
Amethyst: Hardness 7, purple to violet color, vitreous luster, hexagonal crystal system. Orange pieces (likely Calcite): Hardness 3, rhombohedral cleavage, waxy to vitreous luster.
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Physical properties
Amethyst: Hardness 7, purple to violet color, vitreous luster, hexagonal crystal system. Orange pieces (likely Calcite): Hardness 3, rhombohedral cleavage, waxy to vitreous luster.
Formation & geological history
Amethyst forms in geodes within igneous volcanic rocks; Calcite is often sedimentary or metamorphic, forming from precipitation or heat/pressure on limestone.
Uses & applications
Used primarily in jewelry, as decorative collector specimens, and in metaphysical practices.
Geological facts
Amethyst gets its purple color from iron impurities and natural irradiation. Calcite is known for having one of the widest ranges of crystal shapes and appearances in the mineral kingdom.
Field identification & locations
Identify amethyst by its quartz-like hardness and purple hue. Calcite can be identified by its softness (it can be scratched by a copper coin) and its reaction to weak acid.
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