This paper emphasizes the chemical composition and the origin of pyrope from kimberlite and related rocks. Among the 274 chemical analyses of kimberlite and related rocks cited here 78 are supplied by authors. They are calculated, grouped and compared.The preliminary remarks may be given as follows.1. There are two types of garnets in kimberlite. The first type is chrome-chrome-rich pyrope in ultramafic assemblage. For the content of Cr2O3 the purple series generally is greater than 2.5%, orange series is > 0.3%, while the values for garnets from the related rocks are usually lower. Furthermore, the calc-poor, chrome-rich and Fe-low or the calc-high, chrome-rich and Fe-low chrome-rich pyrope associated genetically with diamond may be regarded as ore guide. The second type is pyrope-almandine from eclogite assemblage, of which the composition is commonly hardly distinguishable from that of related rocks, although Mn/Fe2+ + Mn and Na2O differ in content.2. The chemical composition of pyrope from kimberlite shows some successive changes which allow us to infer the mineral studied is derived largely from kimber-litic magma and is polygenetic in nature.
. 1978, 金伯利岩及有关岩类中的石榴石. 地质科学, 13(2): 134-148.
. DISCUSSION ON GARNET IN KIMBERLITE AND RELATED ROCKS[J]. Chinese Journal of Geology, 1978, 13(2): 134-148.