Schultenite from King County, Washington, USA; a second occurrence, and review

AbstractSchultenite, PbHAsO4, known only from Tsumeb, Namibia, has been identified from a second occurrence: near North Bend, King County, Washington, USA. It occurs as euhedral crystals in a quartz-arsenopyrite-galena vein. It has a measured density of 6.07(3) g/cm3and a calculated density of 6.079(4) g/cm3. The white to colourless crystals have a white streak, adamantine lustre, and fluoresce dull yellow under long wave ultraviolet light. Schultenite is monoclinic. Paor P2/a; the unit cell parameters refined from the X-ray powder diffraction data are: a5.827(3), b6.743(3), c4.847(3) Å, ß95.34(5)°; V 189.6(1) Å3; Z = 2; a:b:c= 0.8642:1:0.7188. The forms {010}, {001}, and {3¯22} were observed on the Washington schultenite crystals.