Halotrichite-Pickeringite Series
Copperas Mountain, Paxton Township, Ross County, Ohio, USA
Cliff exposure of Halotrichite-Pickeringite series minerals, called "alum" in the early literature. Puffy, crystalized masses of white efflorescenses are common on the Copperas Mountain cliff exposure. Photo taken September 17, 2009. Field of view, approximately 1 foot across.