There is conclusive mascroscopic and microscopic evidence for the occurrence of monominer-alic topaz rock of magmatic origin in plutonic, subvolcanic, and well-closed facies in nature. Experimental study on the system granite-H2O-RF(R = Li, Na, K, Rb, Cs and H+ ) indicates that monomineralic topaz rock can crystallize from an F-rich magma. Evidently, the rock should be regarded as a new igneous rock. Classification of magmatic monomineralic topaz rock shows that it is advisable to classify it as the category of magmatic greisen. There is every reason to predict that there exist its volcanic analogue in nature, which remains to be discovered and studied. The petrogenetic and metallogenetic model of magmatic monomineralic topaz rock does not negate the development of topazization in rocks. It is not advisable to misuse alteration indiscriminately and exaggerate its ubiquity and importance to petrogenesis and metallogenesis.