一种尚未定名的Ni-As-S-Se矿物相

A DESCRIPTION OF POSSIBLE NEW Ni-As-S-Se MINERAL PHASE

Ni-As－S－Se矿物相首次发现于西秦岭南亚带拉尔玛-邛莫金-铜-铀建造矿床中。与其共生的矿物有：硒汞矿、硒铅矿、硒锑矿、硒硫锑矿、硒硫锑铜矿、自然金、重晶石、石英等。该矿物颗粒细小，粒度小于10μm。在反光显微镜下呈白色，无内反射现象，为一均质矿物。两个点的电子探针分析结果（WB％）：Ni24.123～29．378，As27．574～33．895，Hg7．591～5．359，S13．939～15．560，Sa14．225～12．668等。相应的化学分子式（第二点）为（Ni3.1195Hg0.1665）∑3．2850As2.8199（S3．0251Se1.0000）∑4．0251，简写式Ni3As3（S，Se）4。代表性的反射率值（％）：（470nm）43．02；（550nm）44．80；（590nm）44．80；（650nm）46．82。

The Ni-As-S-Se mineral phase, discovered for the first time in China, occurs in the Laerma-Qiongmo deposit of the gold-copper-uranium formation. Associated minerals include tiemannite,clasthalite, antimonselite, sulfantimonide, lautite, Se-stibioluzonite, native gold, quartz, barite,etc. The mineral forms xenomorphic grains, measuring<10μm in size. Electron microprobe analysis of two points gave the results as follows (WB% ): Ni 24. 123-29. 378, As 27. 574-33. 895, Hg 7. 591-5. 359, S 13. 939-15. 560, Se 14. 225- 12. 668, Cu 0. 268-0. 457, Fe 0.165-0.229, Ag 0. 142-0.058, Co 0.028-0. 000, sum 88. 075-97. 647. For 10 atoms the single analysis corre-sponds to (Ni3. 1195 Hg0.1665)3. 2850 As2. 8199 (S3.02s1 Se1.0000)4.0251 (according to the second point), ideally Ni3 As3 (S, Se)4. In reflected light, white, no internal reflection and bireflectance. Reflectance percent-ages (SiC standard) are given form 400 nm to 700 nm, i. e. representative R values are 470nm,43. 02; 550nm, 44. 80; 590nm 45. 88; and 650nm, 46. 82.