mineral

Green Calcite

Calcium Carbonate (CaCO3)

Hardness: 3 on Mohs scale; Color: Pale green to seafoam green; Luster: Vitreous to waxy/greasy; Crystal Structure: Trigonal/Rhombohedral; Cleavage: Perfect rhombohedral in three directions; Specific Gravity: 2.71

Hardness: 3 on Mohs scale
Color: Pale green to seafoam green
Luster: Vitreous to waxy/greasy

Identified February 14, 2026More mineral →

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Physical properties

Formation & geological history

Formed through sedimentary processes or as a secondary mineral in igneous rocks via chemical precipitation. Carbonate-rich hydrothermal fluids cool or evaporate, often in marine environments or limestone caves, depositing the mineral over millions of years.

Uses & applications

Predominantly used as a collector specimen, in lapidary work (cabochons), and in metaphysical practices. In industrial forms, calcite is used in cement, fertilizers, and as a pH neutralizer.

Geological facts

Calcite is one of the most common minerals on Earth, but the distinct 'acid green' color is specifically caused by chlorite or other mineral inclusions during formation. It exhibits double refraction (birefringence), where light through a clear crystal appears as two images.

Field identification & locations

Identify in the field by its characteristic waxy 'soapy' feel and its reaction to dilute hydrochloric acid (it will fizz). Commonly found in Mexico, Brazil, and the USA. Collectors should look for specimens with a saturated green color and minimal internal fracturing.