70 
GEOLOGY OF THE SECOND DISTRICT. 
the calcareous matter; or whether all the materials were blended together at first, and the 
arrangement effected by molecular attraction afterwards, are questions not easily solved. 
Serpentine, whether pure, or combined with limestone, forms a beautiful and ornamental 
marble. In either variety, it is mottled, striped or spotted, and rarely homogeneous. One of 
the finest varieties of the light clouded serpentine is in Pitcairn. A large quantity of the 
rock has been blasted out, in pursuing a vein of galena. It is, however, far from water 
carriage, and the heavy expense for transportation would exclude it from market. Another 
serpentine, still more beautiful, but nearly black, with light colored veins, has been discovered 
near Butterfield lake in Jefferson county. This is fully equal to the Italian marble, and even 
with its present disadvantages, its distance from water communication, must force its way 
into favor. There is a softness and delicacy about it which makes it superior to what is called 
the Egyptian marble. 
The greatest difficulty in giving a fine polish to the serpentine marble, is the hardness of 
the carbonate of lime, which does not wear so fast as the serpentine ; and hence, there re¬ 
mains a dullness of surface, which does not exist where the substance is homogeneous, as in 
the common marbles ; but by care, and the employment of fine materials for smoothing the 
surfaces in the first place, a perfect polish may be given. 
Origin of Serpentine. 
Most writers place serpentine among the unstratified rocks, and my own observations have 
led me to adopt the same conclusion. By some it has been compared to trap, a rock which 
is found injected among the other masses in the form of veins or dykes. Although serpentine 
is clearly an unstratified rock, and in this respect resembles trap, yet, so far as I have observed, 
it never occurs in injected veins or dykes ; and admitting its igneous origin, it is an interesting 
fact that it should not sometimes thus occur. It is often intimately blended with limestone, 
in which it is found often separated in large and small masses; and when it occurs distinct 
from this rock, it is in irregular beds of a rounded form, never pursuing a range or strike like 
a vein or trap dyke, or the layers which compose a stratified rock. It appears, therefore, in 
great irregular masses, broken into blocks more or less angular, and checked in various ways. 
It becomes brown, or a dirty yellowish brown by weathering, which affects the rock some¬ 
times to the depth of two or three inches. If an igneous rock, it seems to have been poured 
out in the state of thick paste, and at a lower temperature than most igneous rocks when 
projected to the surface. As it dqps not appear in veins or dykes, so it does not appear to 
have altered the rocks adjacent to it. It therefore stands by itself in some respects, being very 
probably an igneous rock. Though not metamorphic, still it is peculiar in the mode of its 
occurrence ; its peculiarity consisting, as before hinted, in its massive character, in its not 
occurring in dykes, nor affecting the adjacent strata like ignited moulten rocks. 
