"MCTO"@en . . . "stable"@en . . . "Microtonalite"@en . . . "Microtonalite - A type of microgranitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of tonalite. British Geological Survey Research Report RR/99/06, section 5.1."@en . . . "Microtonalite"@en .