广东封开蚀变花岗岩中的黑铋金矿

MALDONITE IN AN ALTERED GRANITE AT FENGKAI, GUANGDONG PROVINCE

黑铋金矿产于广东封开蚀变花岗岩中,主要伴生矿物有自然金、自然铋、碲铋矿。该矿物的颜色为银白色,在反光镜下反射色为灰色带黄绿色色调,经能谱分析结果Au=65.28%,Bi=34.72%,计算分子式为Au_(1·995)Bi_(1·000),反射率测定为51.5(405mm),48.9(436nm),50.9(480nm)53.7(644nm),51.9(656nm),42.1(700nm)。对该矿物还作了X射线粉晶衍射分析。

Maldonite occurs in an altered granite at Fengkai, Guangdong Province. The main associated minerals include native gold, native bismuth and tellurbismuthite. The mineral is silver-whlie in color. In the reflecting light it is grey with a yellowish-green tint, Results of the energy dispersive X-ray analysis gave (%)Au=65.28 and Bi=34.72. Its chemical formula is Au 1.995 Bi 1.000. The measured reflective indices are: 51,5(405nm), 48.9(436nm), 50.9(480nm) 53.7(644nm) 51.9(656nm), and 42.1(700nm). The X-ray powder diffraction data are also presented in this paper.