Things You'll Need

Instructions

1

Examine the limestone rock to determine the grain size of the sample. Micrite, a fine-grained limestone, has grains so small that are not visible with the naked eye. Limestones classified as simple fine-grained limestone or micrite do not have fossil inclusions.
2

Identify the presence or absence of fossils in the sample. Fossiliferous limestone is typically a fine-grained limestone with fossil fragments or fossil impressions.
3

View the sample to determine the presence or absence of ooids. Oolites form when layers of calcite accumulate around a sand grain or fossil chip and roll around in deep water and form a calcite sphere. The calcite spheres then cement together with calcite precipitate to form the oolitic limestone. Oolitic limestone looks like a rock with small round spheres covering the surface.
4

Examine the sample for shell hash. Coquina is composed of cemented shell fragments. Unlike, fossiliferous limestone that is a fine-grained limestone with fossils and fossil shells, coquina is composed completely of calcium carbonate shells glued together with calcite or silica.