Charlesite

Formula: Ca6(Al,Si)2(SO4)2[B(OH)4](OH,O)12 · 26H2O

Species:

Colour: Colorless, white

Lustre: Sub-Vitreous, Waxy, Dull

Hardness:

Specific Gravity: 1.77

Crystal System: Trigonal

Member of: Ettringite Group

Name: Named in 1983 by Pete J. Dunn, Donald R. Peacor, Peter B. Leavens, and Jack Leach Baum in honor of Dr. Charles Palache (1869-1954), systematic mineralogist, specialist on minerals of the Franklin District, Professor of Mineralogy at Harvard University, Cambridge, Massachusetts, USA.
Type Locality: Franklin Mine, Franklin, Franklin Mining District, Sussex County, New Jersey – USA