Zinccopperite-A New Variety of Zinc-CopperIntermetallic Compounds Discovered in aPorphyry-Copper Deposit

Abstract: Zinccopperite (tentatively named) is a rare native alloy mineral discovered in quartz monzonite—porphyry in the Xifanping area, Yanyuan County, Sichuan Province. It is a new variety of zinc—copper alloy mineral found for the first time in the porphyry-copper deposit in China. Its intergrown minerals are K—feldspar (mainly perthite), albite—oligoclase, quartz and biotite; and the associated minerals include pyrite and chalcopyrite. It is characterized by a golden reflection colour, being isotropic (isometric), with the grain size ranging from 10 to 50 μm, microhardness VHN₁₀ = 190 kg/mm², and reflectance R_VM = 67.97%. Electron microprobe (Model JXA—733) analysis shows Cu = 59.15%–62.55% and Zn = 36.32%–39.85%. The crystallochemical formula is Cu_6.27-7.0Zn_4.0, simplified as Cu₇Zn₄.