Rock Identifier
Green Calcite or Prasiolite (Green Quartz) (Calcium carbonate (CaCO3) or Silicon dioxide (SiO2)) — mineral
mineral

Green Calcite or Prasiolite (Green Quartz)

Calcium carbonate (CaCO3) or Silicon dioxide (SiO2)

AI-generated identification · may be incorrect

Mohs hardness of 3 (calcite) or 7 (quartz). Light green color, vitreous luster. Calcite has rhombohedral cleavage, quartz has conchoidal fracture.

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Physical properties

Mohs hardness of 3 (calcite) or 7 (quartz). Light green color, vitreous luster. Calcite has rhombohedral cleavage, quartz has conchoidal fracture.

Formation & geological history

Calcite forms in sedimentary environments or hydrothermal veins. Prasiolite often forms by heat treating amethyst.

Uses & applications

Used in crystal healing, collecting, and sometimes faceted into jewelry (especially prasiolite).

Geological facts

Natural prasiolite is rare; most on the market is heat-treated amethyst. Green calcite gets its color from chlorite inclusions.

Field identification & locations

Identify calcite by its softness (scratches with copper penny) and cleavage. Quartz is much harder and scratches glass.