What organic materials make up limestone? What type of mineral and what percent of it determine if a rock is limestone?

Dead organisms make up the organic part of limestone, I am unfamiliar with the second part however.

Limestone is a sedimentary rock composed primarily of calcium carbonate (CaCO 3) in the form of the mineral calcite. It most commonly forms in clear, warm, shallow marine waters. It is usually an organic sedimentary rock that forms from the accumulation of shell, coral, algal, and fecal debris. It can also be a chemical sedimentary rock formed by the precipitation of calcium carbonate from lake or ocean water.