Phosphorite, also called phosphate rock, rock with a high concentration of phosphates in nodular or compact masses. The phosphates may be derived from a variety of sources, including marine invertebrates that secrete shells of calcium phosphate, and the bones and excrement of vertebrates. Related Topics: chemical rock.

Source

It is the most abundant crystalline phosphate mineral found as an accessory mineral in practically all kinds of igneous rocks. Sometimes, it is concentrated in pegmatites, metallic veins and magmatic deposits. It also occurs in metamorphic rocks and as a secondary mineral in phosphatic rocks of sedimentary origin.

USES

Rock phosphate is a vital fertilizer used in agriculture. It is used to make phosphates, a key ingredient in fertilizers, and helps crops grow. Rock phosphate comes from deposits of phosphatic rock and is a natural fertilizer. It can be used as an amendment to soil, water, or spray-on product.