Initially described as a rhombohedral kaolin mineral but later proven to be alunite.
References for Newtonite
Reference List:
Brackett and Williams (1891) American Journal of Science: 42: 11.
Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II. John Wiley and Sons, Inc., New York, 7th edition, revised and enlarged, 1124 pp.: 556, 559.
