Of other natural mineral sources, alunite is the most important.
One of the interesting features of this occurrence is the abundance of alunite.
alunite is a potassium-aluminum sulphate, which differs from sericite in that sulphur takes the place of silicon.
alunite, al′un-īt, n. a mineral consisting of common alum together with normal hydrate of aluminium.
In the Goldfield camp (p. 230) the ores are closely associated with alunite in such a manner as to suggest a common origin.
alunite occurs as veins and replacement deposits, often in igneous associations, and is supposed to be of igneous source.