Geology / History

Calcite is a carbonate mineral & the most stable polymorph of calcium carbonate (CaCO3). The other polymorphs are the minerals aragonite & vaterite. Aragonite will change to calcite at 380–470°C

The largest documented single crystals of calcite originated from Iceland measured 7×7×2 Meters & 6×6×3 Metres & weighed about 250 tons.

Calcite is a common constituent of sedimentary rocks, limestone in particular, much of which is formed from the shells of dead marine organisms. Approximately 10% of sedimentary rock is limestone. Calcite is the primary mineral in metamorphic marble. It also occurs as a vein mineral in deposits from hot springs & in caverns as stalactites & stalagmites. Lublinite is a fibrous, efflorescent form of calcite. Calcite may also be found in volcanic or mantle-derived rocks such as carbonatites, kimberlites or rarely in peridotites.

Calcite is often the primary constituent of the shells of marine organisms e.g., plankton (such as coccoliths & planktic foraminifera), the hard parts of red algae, some sponges, brachiopods, echinoderms, some serpulids, most bryozoa & parts of the shells of some bivalves (such as oysters & rudists). Calcite is found in spectacular form in the Snowy River Cave of New Mexico where microorganisms are credited with natural formations. Trilobites which became extinct a quarter billion years ago had eyes that used clear calcite crystals to form the lenses.

Metaphysical Properties

A very active crystal of unconditional love.Cleaning & clearing its environment. Releases fears, relieves tension & anxiety. Removes any stagnant energy. Combats laziness & allows you to move on. Good for clearing the mind & unblocking old thoughts.

A study stone, hold or place on your desk when wanting to remember. Excellent for pregnancy as it is calming & comforting.

Crystal Healing

Cleans organs, encourages calcium intake, fortifies immune system and skeletal structure.


Group: Carbonate

Crystal System: Trigonal hexagonal scalenohedral

Composition: CaCO3

Form/Habit: Crystalline, granular, stalactitic, concretionary, massive, rhombohedral

Hardness: 3

Cleavage: Perfect

Fracture: conchoidal

Lustre: Vitreous to pearly on cleavage surfaces

Streak: White

Specific Gravity: 2.71

Transparency: Transparent to translucent

R.I: 1.658 and 1.486, respectively

Colour: Colorless or white, also gray & pink

Birefringence: 0.154 - 0.1740.154 – 0.174

Fluorescense: Pink

Solubility: Soluble in dilute acids