Note 2715 — BOOK XXXVI. THE NATURAL HISTORY OF STONES. (continued 2)

Dioscorides says that it was found in Cappadocia also; and both he and Galen attribute to it certain medicinal properties. It was used either for colouring, or else, like fuller’s earth, for taking the grease out of wool and cloth. Ajasson is inclined to think that it was either a volcanic scoria or a Peperite, also of volcanic origin.