Rock phosphate is a rock form of naturally occurring phosphate fertiliser which is formed from sea floor sediments of ancient and current day seas. It is reported as a percentage of phosphorus pentoxide (P2O5).
Phosphates can be deposited in a wide range of marine depositional environments. Normally phosphates are deposited in very shallow, near shore marine or low energy environments.
Rock phosphate can be wet-processed to produce phosphoric acid or smelted to produce phosphorus. Phosphoric acid is reacted with phosphate rock to produce superphosphate or with anhydrous ammonia to produce ammonium phosphate.
The World's largest producers of phosphate are China, America and Morocco.