Abstract:Samples containing alpha-goldarnalgam were collected from the Sanjia gold deposit, Qinglong County, Hebei Province. Alpha-g01damalgam was found in polished sections, heavy mineral samples and bulk ore samples. Electron microprobe analyses indicate that the mineral is composed of Ag 41.53%, Au 22.34% and Hg 36.09%, its average molecular formula is (Ag(2.14)Au(0.63))(2.77)Hg, and its simplified chemical formula is (Ag, Au)3Hg. Au, Ag and Hg are uniformly distributed in the mineral. Alpha-goldamalgam occurs as very fine spherio particles or irregular gra, nular aggregates with bright yellowish white color, strong metallic luster and low hardness(Vickers hardness 92.23 kg/mm2, corresponding to Mohs' hardness 3.05). Under microscope it is homogeneous with rosy bright yellowish white and bright white colors but without double reflection and pleochroism. The reflectance data are as follows: Wavelength (nm) 480 546 591 654 Reflectance (%) 76.22 82.70 86.35 89.05 Its X-ray powder analytical data are 2.382(9)(111),2.060(6)(200),11461 (7)(220),1.245(10)(311) and 1.194(5)(222), comparable with the data of alpha-gold-merCury. Its crystal structure is of isometric system with a being 4.129 and space group Fm3m.