. "PHMST"@en . "Phosphate-mudstone"@en . . "Phosphate-mudstone - A type of phosphorite, classified on the basis of its depositional texture. In the Rock Classification Scheme, it is a matrix-supported phosphorite composed of greater than 75% matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 4.2, table 11 and fig. 8."@en . . . "stable"@en . . "Phosphate-mudstone"@en . .