20 R. Pumpelly— Pseudomorphs of Chlorite. 
wholly dark during a revolution, some show only a faint 
change, and others are not distinguishable from the substance 
forming the bands, except that the cleavage lines are not so 
distinct. So also with one nicol, the portions that remain 
dark between crossed nicols show no absorption, while other 
portions change from clear green to almost colorless faint 
green-yellow, and still others show about the same changes as 
the bands. | 
Again, we find in places, on the same individual, all these 
conditions, shading gradually one into the other in a manner 
that, seems to indicate a bent crystal. I am inclined to look 
upon the bands and the clear green as identical, and as belong- 
ing to a hexagonal chlorite. The green portions would then 
be those which were cut more or less parallel to the basal 
plane, and the dichroitic bands those cut perpendicular to this. 
ile the plane of contact between the chlorite bands an 
garnet appears sharp under a low power, higher objectives (one- 
tenth or one-sixteenth inch) show it to have a rough surface 
caused by the projection of countless chlorite points into the 
garnet substance, in a manner that leaves on the observer the 
irapression that the attack is facilitated in some way by the 
curdled structure of the garne 
The chloritic schist which encloses the pseudomorphs con- 
sists apparently of exactly the same chlorite, the only percep- 
tible difference being that in the schist the individuals are very 
If this view is correct, the paragenesis should be as follows: 
I. Ortemvat Rock ( ?) 
