1914] Certain Mineral Resources 17 



areas of hornblende-gneiss, mica-schist, and quartz-schist are 

 developed. Peridotites are found inclosed by or in contact with 

 all of these various types. On account of greater resistance to 

 weathering it often happens that hornblende-gneiss is most con- 

 spicuous in outcrops, even where relatively unimportant in 

 extent. Hence it has often been reported that the peridotites 

 are always, or at least in most cases, associated with hornblende- 

 schist. 



The corundum found in these peridotites does not occur as 

 accessory mineral or a rock constituent, but is concentrated 

 either near the contact of the peridotite and the inclosing 

 gneissic rocks or in pockets within the mass of the peridotite. 

 A series of secondary minerals, however, has been developed 

 both along the contacts and with the corundum masses within 

 the peridotite, so that the corundum is not found in direct con- 

 tact with either the peridotite or the gneiss, nor are these rocks in 

 contact with each other. The secondary minerals are chiefly chlo- 

 rites, vermiculites, enstatite, and talc, and are not in any sense 

 the results of contact metamorphism. It is customary to refer 

 to these corundum-bearing zones as " veins," and that term is 

 used here merely for convenience, without implying any par- 

 ticular character or origin. Those occurrences about the borders 

 of the peridotites are designated as " border veins," and those 

 wholly within the peridotite as " interior veins." Corundum 

 has been found in such deposits in ISTorth Carolina, Georgia, and 

 Alabama. 



At all of the corundum localities examined a careful search 

 has been made to find corundum directly surrounded by the 

 peridotite, but this has been observed at only one locality — the 

 Egypt Mine, on the western slope of Sampson Mountain, in 

 Yancey County, N. C. The few specimens obtained were col- 

 lected by Mr. U. S. Hayes, who developed the corundum prop- 

 erty in that section. One specimen shows a prismatic crystal of 

 the corundum surrounded by a granular peridotite (dunite), 

 but with none of the chlorite minerals which usually intervene. 

 The dunite is not quite fresh, but is stained a yellowish brown 

 by iron oxide and is rather friable. On the basal surfaces of the 



