Formula: (K,Na,Ca,Ba)4-7(Al4-7Si12-9)O32.12H2O Monoclinic
Description: Phillipsite is a member of the zeolite family. It occurs most frequently in vein and amygdule fillings in basaltic rocks. It also forms during shallow burial of volcanic rocks, particularly ashes and glasses.
DOUGLAS COUNTY: Phillipsite has been tentatively identified in thin veins with natrolite (?) and calcite in gouge cutting basalt along the Douglas Fault exposed along the banks of the Amnicon River in Amnicon Falls State Park (SE sec. 29 T.48N. R.12W.) (Ludvigson and Anderson, 1986).