邛莫金矿床中的硒辉锑矿

硒辉锑矿产于西秦岭邛莫金矿床中。与其共生的矿物有灰硒汞矿、灰硒铝矿、硒锑矿、硒块硫锑铜矿、硒镍矿、自然金以及石英、重晶石等。该矿物显微硬度VHN50＝68．25～128．0kg／mm2，平均101．26kg／mm2，相当于摩氏硬度3．15、30个测点的电子探针分析结果（％）：Sb57．75～66．79（平均63．25），S11．86～21．62（平均17．30），Se12．82～29．12（平均19．27），据其平均值计算的化学分子式为：Sb1．99（S2．07，Se0．93）3．00，简写式为Sb2（S，Se）3。代表性的反射率（％）：（470nm）Rα’＝45．33，Rγ’＝31．03；（550nm）Rα’＝46．75，Rγ’＝33．63；（590nm）Rα’＝46．06，Rγ’＝：33．50；（650nm）Rα’＝45．18，Rγ’＝31．49。对两个Se含量仅达3％～5％的辉锑矿粉晶分析所得晶胞参数值为：a＝1．1209～1，1212nm，b=1．1299～1，1303nm，c＝0．3847～0，3849nm。与辉锑矿相比十分相似。

Se-STIBNITE FROM QIONGMO GOLD DEPOSIT IN WESTERN QINLING, CHINA

Se-stibnite was discovered in the Qiongmo gold deposit occurring in the Cambrian sili-calite and slate in the south subzone of western Qinling Mountains. Samples containing Se-stibnite were collected from the silicalite-type ores. Se-stibnite was found in quartz-barite veins in the form of dissemination or veinlet. The associated minerals include tiemannite, clasthalite, antimonselite,Se-stibioluzonite, native gold, barite and quartz. The mineral is lead-gray in colour, metallic in luster and brashy,0. 01-0. 2 mm in size, 68. 25- 128.0kg/mm2(for 50 g load ) in microhardness and Moh's = 3. 15. The reflectance values (SiC standard ) are given in 10 nm steps. The represen-tative R values are 47o0nm R'a= 45. 33, R'Y= 31. 03; 550 nm R'a= 46. 75, R'Y= 33. 63; 590nm R'a= 46. 06, R'Y= 33. 50; 650 nm R'a= 45. 18, and R'Y= 31. 49. Electron microprobe analyses of thirty points gave the results as follows (% ): Sb 57. 75% - 66. 79% (63. 25% on average ), S 11. 86% -21. 62% (17. 30% on average), and Se 12. 82% - 29. 12% (19. 27 % on average), pre-senting a formula of Sb1.99(S2.07, Se0.93)3.00 and its simplified formula is Sb2 (S, Se )3. The unit-cell parameters of Se-bearing stibnite are a = 1. 120 9- 1. 121 2 nm, b=1. 129 9 - 1. 130 3 nm,c=0. 384 7-0. 384 9 nm, which are similar to those of stibnite.