1) Industrial mineral 
Phosphorite, phosphate rock or rock phosphate is a non-detrital sedimentary rock which contains high amounts of phosphate bearing minerals. The phosphate content of phosphorite is at least 15 to 20%, which is a large enrichment over the typical sedimentary rock content of less than 0.2%. The phosphate is present as fluorapatite Ca5(PO4)3F (CFA) ty...
• (n.) A massive variety of apatite.
rock with a high concentration of phosphates in nodular or compact masses. The phosphates may be derived from a variety of sources, including marine ... [10 related articles]
Phos'phor·ite noun (Min.) A massive variety of apatite. 
Phosphorite is an impure massive form of apatite, mined for the calcium phosphate it contains, and forming one of the chief sources of phosphorus and its compounds, and of artificial manures.