黄锡矿-似黄锡矿-硫锡铁铜矿组合及其结构特征

STANNITE-STANNOIDITE-MAWSONITE ASSOCIATION AND ITS TEXTURAL FEATURES

黄锡矿-似黄锡矿-硫锡铁铜矿产于湖南大义山花岗岩与石炭、二叠系灰岩接触处的富斑铜矿夕卡岩铜矿床中。硫锡铁铜矿在国内属首次发现。它们的化学成分、物理性质、光学性质和晶体结构与国外相同矿物相似。它们都有两种产状,构成多种结构。

Stannite, stannoidite and mawsonite occur in the bornite-rich skarn ores at the contact between the Carboniferous-Permian limestones and the Dayishan granite at Changning County, Hunan Province.They are associated with sphalerite, co-loellingite, coarsenopyrite, chalcopyrite, bornite, chalcocite, wittichenite, stromeyerite, cassiterite, etc. Their composition, physical property, optical property and lattice structure are similar to those of the equivalent minerals occurring both in Changning and abroad.There are two types of occurrence. Stannite is granular in form(>0.5mm), with stannoidite appearing on the margin and, in some cases, myrmekitic texture observed because of partial ion substitution as a result of the action of copper-rich solutions, followed by the precipitation of chalcopyrite, giving rise to lacelike texture.For the other type of occurrence, stannite, stannoidite, maw sonite and bornite occur in exsolution intergrowths of chalcopyrite, exhibiting graphicmyrmekitic texture or grid texture.Additionally, stannite also exhibits chess-board and mosaic textures. It seems to be the exsolution intergrowths of Zn-rich and Fe-rich stannite.