natroalunite
Mineralogy
noun
Any of the range of hexagonal basic hydrated sulphates of sodium, potassium, and aluminium, (Na,K)Al3(SO4)2(OH)6, which have the proportion of sodium greater than that of potassium and are found as white crystals; specifically the sodic end-member of this series.
Origin
Early 20th century. From natro- + alunite.