Formula: (Mg,Fe)Al2(PO4)2(OH)2 Monoclinic
Lazulite is a rare bright blue mineral which can occur aluminum-bearing quartzites, quartz veins or granite pegmatites.
SAUK COUNTY: Olsen (1962) reports a 2 mm thick vein of lazulite cutting through a block of Baraboo quartzite found on a talus slope above Devil’s Lake in Sec. 30 T.11N R.7E, about 10 km south of Baraboo. Analysis of the lazulite showed that it also contained significant nickel and cobalt.