Chemical and isotope data were obtained for the active gas and noble gas of inclusion fluids in coarse-grained samples of magmatic-hydrothermal and magmatic-steam alunite from well-studied deposits (Marysvale, Utah; Tambo, Chile; Tapajós, Brazil; Cactus, California; Pierina, Peru), most of which are discussed in this Volume. Primary fluid inclusions in the alunite typically are less than 0.2 Am...