Chalkis the name of a limestone that forms from an accumulation of calcareous shell remains of microscopic marine organisms such as foraminifera. It can also form from the … See more

Coquinais the name of a poorly cemented limestone composed almost exclusively of sand-size fragments of calcareous shell and/or coral debris. A small amount of calcareous cement … See more

When limestone is subjected to heat, pressure, and chemical activity, the calcite in the rock begins to transform. This is the beginning of the process known as metamorphism. Starting at a microscopic scale, the calcium carbonate in the rock begins to crystallize or recrystallize into fine-grained calcite crystals. As the duration and intensity of ... See more

Dolomitic limestone is a rock composed mainly of calcite, but some of that calcite has been altered to dolomite. Dolomite is thought to form when the calcite (CaCO3) in carbonate sediments or in limestone is modified by magnesium-rich groundwater. The available magnesium facilitates the conversion of calcite into dolomite … See more