Judging from the literature during the past decade, there is a growing interest in problems related to the genesis of carbonatites and associated alkaline igneous rocks. The interest has undoubtedly been fostered by the discovery of large reserves of rare earths in these rocks. Many field geologists believe that carbonatites were emplaced as liquid magmas; but hitherto there has been no conclusive experimental evidence to support the existence of carbonatite liquids. In fact, from the available experimental evidence it seemed unlikely that such liquids could exist at the low temperatures indicated by field studies. We have recently obtained experimental evidence that simplified carbonatite magmas can exist at moderate temperatures through a wide range of pressures.