Natroalunite and alunite from white island volcano, bay of plenty, New Zealand

Abstract

Alunite minerals were found on White Island volcano, Bay of Plenty, New Zealand. Most samples contain natroalunite with a subordinate amount of alunite; sodian alunite was identified in two samples. The minerals occur in microscopic and submicroscopic euhedral crystals. Chemical, X-ray, and DTA data are given. The minerals probably formed by alunitisation of volcanic rocks, rather than by direct precipitation from hot waters. © 1975 Taylor & Francis Group, LLC.