The '''sulfates''' are [[compounds]] of one or more [[metallic]] [[elements]] with the [[sulfate]] radical. This is a large class of [[minerals]], whose members have few [[properties]] in [[common]]. In general they are light in [[color]] and [[transparent]] to [[translucent]]. None are hard, and most are [[fragile]]. Chesterman, p. 453
=Sources=
*Chesterman, Charles W. ''The Audubon Society Field Guide to North American Rocks and Minerals'', Alfred A. Knopf: New York (1987)