a mineral composed of Bi. It crystallizes in trigonal system; granular formations and feathery and branching dendrites are characteristic. It has complete cleavage. It is silver-white on a new fracture, with a yellow tint and usually with reddish iridescence. Its hardness on the mineralogical scale is 2.5; its density is 9,780-9,830 kg/m3. Native bismuth is formed in skarn and hydrothermal deposits in association with cassiterite, wolframite, molybdenite, scheelite, and sulfides of Pb, Zn, Cu, and Fe, as well as in ores containing sulfides and arsenides of Co and Ni, pitchblende, and native silver.