Electron-microprobe analyses of the mineral and of an antimony-bearing variety gave Au 32.6, 34.3, 36.7, Ag 0.35, not detected, Pb 64.8, 59.0, 52.9, Sb 0.3, 5.8, 10.2, sum 98.05, 99.1, 99.8 wt%, corresponding to (Au1.051 - Ag0.022)Σ1.073 (Pb1.985Sb0.015)Σ2.000, Au1.049(Pb1.713Sb0.287)Σ2.000, and Au1.101 (Pb1.507Sb0.493)Σ2.000. Fragments are opaque, silvery gray, luster metallic. Oxidizes after 1.5–2 days, be- coming dull lead-gray. In reflected light, light gray (silvery) with a faint creamy tint, fairly highly reflecting; bireflectance barely noticeable; commonly oxidized, be- coming dark gray with a blue-black cast and poorly reflecting. Weakly anisotropic from silvery gray to gray. The antimony-bearing variety is indistinguishable opti- cally but is slightly less reflecting than anyuiite proper, for which Ra, and Re at 20-nm intervals (WTiC standard) are: 420 56.7, 50.3; 440 59.0, 52.9; 460 60.7, 55.0; 480 62.0, 5 6.2; 500 62.4, 57 .7; 520 63.2, 58.3; 540 63.9, 59.3; 560 64.6,59.9; 580 65.1, 60.7; 600 65.6, 61.4; 620 66.0, 62.1; 640 66.1, 62.6; 660 66.2, 63.0; 680 66.5, 63.4; 700 66.8, 63.7. VHN20 = 146 (range 142–152.8), decreasing to 101 (range 100.8–104) for the antimony-bearing variety. Plastic and malleable, nonmagnetic. The mineral is too fine grained for single-crystal study. By analogy with synthetic AuPb2, tetragonal, space group I4/mcm. From powder-diffraction data, a = 7.39(2), c = 5.61(3) Å, Dcalc = 13.49 g/cm3 with Z = 4. Lines attributed to the mineral are 5.22(60,110), 3.74(20,200), 2.82(10,002, possibly this reflection is a sum of 002 and 211), 2.59(20,220), 2.48(10,112), 2.23(30,202), 1.155(20,433), and 1.130-(20,541). The remaining six lines in the pattern (intensity ranges from 20 to 50) are attributed to gold.

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