239 
that the quartz in granulites instead of comporting itself as in 
granites, that is moulding upon or embracing the other minerals, 
is isolated, brittle, and often rounded; and sometimes is met 
with even in the form of bi-pyramidal crystals. The granulites 
contain an alkaline felspar Orthoclase, and the plagioclase 
felspar, oligoclase; the latter oftentimes more abundant, and 
the two felspars are vitreous. Black mica is sometimes present, 
and white mica in variable quantity ; garnets are also accessory. 
The lacune of the quartz enclose movable bubbles, or fixed 
bubbles surrounded by very thick black rings. The jointing of 
the granulites is noticeable, for besides the principal horizontal 
and tabular jointing, these regular horizontal courses are 
intersected at right angles by cross joints, somewhat crooked, 
but with smooth surfaces, which give it a striking and 
characteristic look, so that, by this aspect alone it may be 
distinguished from gneiss at a considerable distance, (according 
to B. von Cotta). 
Short separate descriptions are here intentionally given of 
some granulites citing and noticing them in the following 
sequence :— 
1. L’Ardéche. 8. Malvern. 
2. Jersey. 4. Dresden. 
1. Granvuiire rrom L’ARDECHE— 
The specimen of this granulite was brought from the 
Department of L’Ardéche, in France, from an exposure of this 
rock on the route which crosses the basaltic plateaux of some 
4,000 feet or more going from the Béage, on the descent to 
Montpezat; the quarry of this stone lies to the left hand of the 
winding road. This specimen shows the well-marked rounded 
granular state, the felspars Orthoclase and Albite are an opaque 
white, the quartz vitreous and small in quantity, the grains are 
coated in patches with bright red oxide of iron ; it often contains 
bi-pyramidal crystals of quartz. 
2. GRANULITE FROM CHANNEL IsLANDS— ‘ 
A typical granulite is that of Mount Mado lying to the 
Northward of Jersey, often by the earlier geologists mentioned 
