this stone. Bliimner292 thought it was magnetite, and Stephanides293 suggested marcasite, but both identifications are improbable, for Theophrastus is speaking here of a stone that can be worked on the lathe, and the brittleness and hardness of both these minerals would prohibit the use of such a technique, especially with the appliances available to the ancients. Stillman294 suggested that it might have been marble, dolomite, or gypsum. Though it is not improbable that gypsum in the form of alabaster might be intended, the most likely conjecture was made by Moore,295 who believed tJiat the Magnesian stone of Theophrastus was a form of talc. This identification best fits the conditions to be fulfilled: it was a soft mineral substance that could be easily turned on a lathe, it was available in large pieces, and it was white and in some way resembled silver. Some varieties of this hydrous magnesium silicate exhibit a characteristic white pearly or silvery luster. The stone mentioned in the next section was probably an impure form of the same mineral.
42. In Siphnos there is a stone of this \ind which is dug up about three furlongs from the sea.
Siphnos is an island in the Aegean Sea northeast of Melos. Three stades, here translated as furlongs, are equivalent to about 1,820 feet. Pliny296 is the only other ancient author who describes the stone found on Siphnos, and he appears to have obtained his information about it mainly from the present passage, though he adds that the green stone found at Comum (modern Como) in northern Italy was put to the same uses. It seems probable that this stone found on Siphnos was the variety of impure steatite or soapstone called potstone, usually greyish green to dark green in color and so soft that vessels of almost any shape can easily be carved from it. Though Fiedler297 was unable to obtain any evidence that potstone occurred on the island, this does not prove it
292 Technologic und 7'erminologie ier Gewerbe und Kiinste bet Griechen und Romern, Vol. Ill, p. 278.
293 The Mineralogy of Theophrastus, p. 159.
294 J. M. Stillman, The Story of Early Chemistry (New York, 1924), p. 72.
295 Ancient Mineralogy, p. 156.
296 XXXVI, 159.
297 Cited by Bliimner, Technologic und Terminologie der Gewerbe und Kiinste bet Griechen und Romern, Vol. Ill, p. 66.
