碲砷黝铜矿在我国的首次发现及其找矿意义

The First Discovery of Tellurian Tennantite in China and Its Significance to Ore Prospecting

碲砷黝铜矿产于广东陆丰中低温热液蚀变岩型硫铁矿床中．该矿物呈浑圆状、不规则状嵌布在黄铁矿内，粒径０．０２－０．２０ｍｍ，铅灰色，硬度Ｈ＿ｖ＝２６９．３ｋｇ／ｍｍ￣２，反射色呈灰色微带棕色色调，均质性。两个颗粒电子探针成分分析：Ｓ２４．５５％，Ｃｕ４１．０６％，Ａｓ９．８６％，Ｔｅ１８．２９％，Ｓｂ３．５８％，Ｆｅ２．５０％，Ｚｎ０．１１％，Ａｇ０．０３％，化学式为：（Ｃｕ＿（９．９９５）Ａｇ＿（０．００５））＿（１０）（Ｆｅ＿（０．７３７）Ｃｕ＿（０．６３２）Ｚｎ＿（０．０２３））＿（１．３３８）（Ａｓ＿（２．１６５）Ｓｂ＿（０．４３４）Ｔｅ＿（１．９５２））＿（４．６０）（Ｓ＿（１２．５８５）Ｔｅ＿（９．４９５））＿（１３）．Ｘ射线分析主要粉晶谱线２．９４５，２．５６３，１．８７５，１．７５９，１．０５６，晶胞参数ａ＝１０．２２３，碲砷黝铜矿的发现，可作为在该地区寻找伴生碲矿床的重要标志。通过初步分析，黄铁矿矿石内碲已达综合利用品位。

Tellurian tennantite, a rare sulfosalt mineral, was discovered for the first time in a pyrite deposit related to mesothermal一 epithermal alteration in Lufeng County, Guangdong Province,As an isotropic mineral, it occuts as irregular grains embedded in pyrite, is lead grey in color and 0.02-0.20 mm in size, and has a Rockwell hardness of 269.3 kg/mm￣2, with reflection color being grey with a bit brown tone. The associated minerals include tellurobis-muthite and wittichenite. Electron microprobe analysis shows the mean chemi-cal composition of the mineral to be S 24.55%, Cu 41. 06%, As 9.86%, Te 18.29%, Sb 3.58%, Fe 2.50%, Zn 0.11%, and Ag 0.03%, making up a chemical formula of (Gu_(9.995)Ag_(0.005))_(10)(Fe_(0.737)Cu_90.633) Zn_(0.028))_(1.398) (As_(2.165)Sb_(0.484) Te_(1.952))_(4.60)(S_(12.505) Te_(0.405))_(13). According to X-ray diffraction analysis, its stron-gest powder lines are 2.945 ,2.563,1.875,1.759 and 1.056,and its unit cell parameter a = 10. 223( ). Planar distribution of elements, reflectance and hardness were determined besides electron microprobe and X-ray diffraction analyses. It is indicated that tellurian tennantite represents a mineral species of tetrahedrite, and might be nsed as an important indicator mineral in search for tellurium deposits asso-ciated with pyrite deposits. In fact, the tellurium grade of the mineral has come up to the standard for comprebensive utilization.