山东蒙阴金刚石晶体特征及其形成条件

Characteristics and Formation Conditions of Diamond Crystals in Mengyin County of Shandong Province

摘要:

为探讨山东蒙阴金刚石的形成条件和生长过程，总结了前人对金刚石晶体形态、表面形貌、内部生长特征和包裹体的研究成果。结果表明，蒙阴金刚石晶体形态以平面八面体、阶梯状八面体、八面体与曲面菱形十二面体聚形和曲面菱形十二面体四类形态为主，晶体上常见与晶体的生长过程或与晶体形成后的塑性变形、溶蚀作用有关多种类型表面形貌，晶体内部可见两期生长或多期生长结构，晶体中常见的包裹体类型有石墨、橄榄石、铬铁矿、镁铝榴石、铬透辉石等。多样化的晶体特征指示了金刚石形成和生长过程中物理化学条件变化的复杂性。

Abstract:

In order to study the formation conditions and growth process of the diamond in Mengyin county of Shandong province, previous research results on the crystal morphology, surface morphology, internal growth characteristics and inclusions of diamond have been summarized in this paper. It is showed that the crystal morphologies of Mengyin diamond are mainly four types of morphology, they are plane octahedron, stepped octahedron, polyshaped of octahedron and curved rhombic dodecahedron, curved rhombic dodecahedron. The surface morphologies of Mengyin diamond crystals are usually related to the growth process of the crystals, plastic deformation and dissolution after crystal formation. Twostage growth or multistage growth structure can be seen in the crystal. Graphite, olivine, chromite, magnesiaalumina garnet and chrome diopside are the common inclusions in the crystal. The variety of crystal characteristics indicates the complexity of physical and chemical conditions during the formation and growth of diamond.