How is calcite created?

The most common is as tiny crystals or fossil fragments that comprise limestone. Calcite can form by direct precipitation from waters rich in calcium. As concentrations increase or the amount of water decreases crystals of solid calcite crystals form. Organisms make structural elements or shells.

How does calcite form on the surface?

Chemistry. Calcium carbonate is known to precipitate as calcite crystals in water supersaturated with calcium and carbonate ions. Under quiescent conditions, calcite crystals can form on a water surface when calcium carbonate supersaturation conditions do not exist in the bulk water.