含锡自然铜研究

本文对发现于河南毛堂金矿田氧化矿石中的含锡自然铜进行了矿物学研究。该矿物属等轴晶系,O_h~5-F_(m3m),a_0=3.655?,Z=4。化学成分中Cu 90.38(wt)%,Sn 9.38(wt)%,分子式Cu_(18)Sn。含锡自然铜相当于Cu_(18)Sn合金中的a相,在自然界属首次发现。

A Study on Stanniferous Native Copper

Stanniferous native copper was discovered in 1983 in some oxidized ores ofthe Maotang gold field in Xichuan, Henan Province. It occurs in brecciated gold.-bearing granite porphyry as fine-grained aggregates 0.06--0. 15mm in size withkaolinite, limonite and native chromium as associated minerals and feldspar,quartz, pyrite and native gold as accompanying minerals. It is bronze in colorand metallic in Iustre. It has microhardness of 184--189kg/mm_2 and specificgravity 9.04 (calc.). Under reflected light, it assumes reddish yellow colour,reflectance values being 33.43 (470nm), 46.78 (546nm), 58.77 (589nm) and 65.21(650nm). The stronger lines in X-ray diffraction are 2.1608 (10), 1.8235 (7), 1.2932(5) and 1.1022 (5), showing this mineral to be isometric with space group O-h~5-Fm3m and unit cell a_0=3.655 A and Z=4. The chemical composition as determined by electron microprobe analysis is93.38% Cu and 9.38% Sn, giving a chemical formula of Cu_18Sn. Stanniferous native copper, equal to a-phase of Cu-Sn alloy, is discoveredfor the first time in nature,