金刚石分类、组成特征以及我国金刚石研究展望

金刚石由于其独特的物理化学性质，在经济生产与科学研究中均具有重要价值.金刚石形成于地球大于150 km的深度范围内，是人类可以获得的来自地球深部地幔乃至核幔边界的最直接的样品，因此可以为研究地球深部物质组成和物理化学条件提供重要的素材.金刚石由碳元素组成，还含有微量的杂质元素（如氮、硼、氢、氧等），其中氮和硼元素对于划分金刚石的晶体结构类型发挥着重要的作用.根据金刚石的产出类型，金刚石可以划分为幔源型、超高压变质型、陨石相关型以及蛇绿岩型金刚石.全球约百分之一的幔源型金刚石含有包裹体，对这些包裹体的研究显示，金刚石主要来源于地球150~200 km深度的岩石圈地幔.这些含有包裹体的金刚石中，仅有1%的金刚石来自于地球深部的软流圈、地幔过渡带、下地幔、甚至核幔边界.我国的金刚石产出类型多样，但是，目前仅山东蒙阴、辽宁复县的金伯利岩矿床以及湖南沅水的砂矿具有经济价值.蛇绿岩型金刚石是近年来金刚石研究领域取得的重要进展，该类型金刚石分布在全球多个造山带不同时代、不同构造属性的蛇绿岩地幔橄榄岩和铬铁矿中，被认为是一种新的金刚石的产出类型.相对于其他国家和地区的金刚石的研究，我国的金刚石领域的研究程度相对较低，缺乏对金刚石结构、化学组成以及包裹体组成的系统研究，制约了对我国金刚石成因的认识，限制了我国的金刚石的找矿工作.因此，亟需结合先进的分析手段对我国的金刚石及其围岩做进一步的研究，以期揭示金刚石的形成过程，为金刚石的找矿提供理论基础. 

Diamond Classification,Compositional Characteristics,and Research Progress: A Review

Due to the unique physicochemical characteristics, diamonds are of great significance in economic production and scientific research. Diamonds record valuable information about the physicochemical conditions and compositions of Earth's deep mantle and even the core-mantle boundary. Diamond mainly consists of carbon, with minor impurities such as nitrogen, boron and hydrogen. Of these impurities, nitrogen and boron play important roles in the classification of diamonds. Carbon and nitrogen are vital elements for life, the cycles of which are closely related to the environment that humans live in. Diamonds can provide clues for the deep carbon and nitrogen cycle on the Earth. Studies on the mineral inclusions show that diamonds mainly form between a depth window of 150-200 km, with 1% of the diamond population forming in the asthenosphere (>200 km), the mantle transition zone, the lower mantle or even the core-mantle boundary. China hosts different types of diamonds, however, diamonds of economic significance only exist in the Shandong Province and Liaoning Province. The discovery of ophiolite-hosted diamonds (also called ophiolitic diamonds) is an important progress in the study of diamonds. Ophiolite-hosted diamonds in China have been discovered in ophiolitic peridotites and chromitites in different orogenic belts, and have been accepted as a new occurrence for diamonds. Diamond research in China is very limited, which has hampered the understanding of diamond genesis and diamond exploration. New analytical methods need to be applied on diamond and country rock research to provide new constraints on diamond formation and theoretical basis for diamond explorations.