keith] TALC DEPOSITS OF NORTH CAROLINA. 435 
all of the weathered, or semiweathered portions, which are near the 
surface. In the talc which is secured by mining from the solid rock 
light colors prevail, varying from bluish and greenish white to a 
dull blue and a pale green. The freshest mineral is translucent. 
This character has been lost by all of the weathered talc, which is 
perfectly opaque. Much of the weathered material is also stained 
with iron oxide from the ferruginous minerals in the schists which 
border the marble formation. This rust coats and stains the surface 
of the fragments and penetrates into their interior by cracks and 
seams. It is a serious detriment to the quality of the talc, since it is 
mixed throughout the latter when it is ground. 
As can be readily understood from the dimensions of the talc lenses, 
the quantity of the talc varies greatly. It is only by actually working 
out each body or by thoroughly testing by diamond drill that any idea 
of the amount can be obtained. A lens whose edge only can be seen 
is as likely to be large as small. It is equally impossible to predict 
where a mass of talc will or will not be found. Many of the miners 
say that the talc is always overlain by a white sandstone called the 
"cap rock." This is often the case, but is not the rule, for the talc 
is frequently formed where there is no associated sandstone. The 
talc lenses are not confined to one horizon in the marble, but may 
appear between several distinct layers. Variations in the quality of 
the talc are considerable, also, even in the same bod}^ of marble. 
For instance, at Hewitt's mine on Nantahala River both the massive 
and the fibrous varieties are found, as well as the blue, green, and 
white colors. One quality and color usually predominate in a single 
lens or sheet. 
The texture and grain of the talc are very variable, even in the same 
group of lenses, as was just stated in reference to the Hewitt mine. 
The talc scattered through the mass of the marble is usually in the 
shape of foliated scales. The same is true to a greater or less degree 
of the thin edges of the various lenses. Some of the thicker lenses 
are composed practically entirely of massive talc. This has no cleav- 
age or tendency to part in one direction rather than another, and is 
sawed into pencils and sheets. Most of the talc has a tendency to 
break into long, thin fragments, flakes, and fibers. 
Inasmuch as the methods of manufacture of the talc depend upon 
its softness, any impurities which affect that quality are a detriment. 
Other impurities, such as stains by iron rust and soil, were spoken of 
above. These can be removed, however, in part. The principal 
impediments to the working up of the talc are the associated min- 
erals, mostly silicates. These are inclosed in the mass of the talc in 
crystals arranged at a great variety of angles. The silicates consist 
ehiefty of hornblende, tremolite, actinolite, and chlorite, all contain- 
ing a certain large percentage of magnesia. There are also found 
