山东省郯城地区金刚石砂矿中绿色金刚石特点与宝石学意义

Characteristic and Gemmological Signification of Green Diamond in Tancheng Diamond Placer of Shandong Province

山东郯城金刚石砂矿区赋矿层是第四系于泉组。通过论述的主要矿体地质特征、绿色金刚石特点,对金刚石绿色的地质成因进行了初步探索。通过分析已知绿钻晶特点,研究认为整体绿色是由于岩浆期地质辐照致色,层态和斑点绿色是岩浆期后和砂矿期的地质辐照致色。整体绿比壳层绿、斑点色更适宜做宝石应用;纯正绿色晶体具有更高价值;透明度低的绿色晶体也是宝石应用的好材料。

The ore bed in the Tancheng diamond placer area is the Quaternary spring forma-tion. Based on the geological features of the main ore bodies and the characteristics of green diamonds, the geological origin of the green diamond has been preliminarily explored. Through the analysis of the known diamond crystal characteristics, we consider that the whole green was due to magmatic geological irradiation. Geological radiation of magmatic and placer periods leads to both layer and green spots. Entire green is more suitable for gem application than shell green and spot color; pure green crystals are of higher value, and poor transparency green crystals are also good materials for gemstone applications.