燐りん灰かい岩がんMeanings1nounphosphate rock; phosphoritegeologyGeological term for a sedimentary rock rich in phosphate minerals, used mainly in fertilizer production.燐りん灰かい岩がんはリン酸さん肥ひ料りょうの原げん料りょうとして重じゅう要ようである。Phosphate rock is important as a raw material for phosphate fertilizers.