Dark Limestone

Limestone

Limestone is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate CaCO3. Limestone forms when these minerals precipitate out of water containing dissolved calcium. This can take place through both biological and nonbiological processes, though biological processes, such as the accumulation of corals and shells in the sea, have likely been more important for the last 540 million years. Limestone often contains fossils which provide scientists with information on ancient environments and on the evolution of life.

Darkness

Darkness is the condition resulting from a lack of illumination, or an absence of visible light.

dark

Adjective

1. Having an absolute or (more often) relative lack of light.
2. Extinguished.

Noun

1. A complete or (more often) partial absence of light.
2. Ignorance.

limestone

Noun

1. An abundant rock of marine and freshwater sediments; primarily composed of calcite (CaCO3); and occurring in a variety of forms, both crystalline and amorphous.