22: 
figure of it at the bottom of the plate on ‘the left hand, 
showing the form of the fractured rhomb, and the lower 
side of a prism with a triangular face, formed of a bevilling 
from the edge of the sharpest angle of the side of the 
truncated end, as in the little middle crystal, which also 
shows the parallel fractures. or flaws. The right hand 
modification is rather more common; viz._a six-sided co- 
lumn with two terminal faces, one primitive, or parallel 
to the fracture of the crystal, as in those before spoken of ; 
and two directly opposite, forming at each end of the prism 
one primitive face and one opposite truncation, alternating 
with those at the opposite end. 
These are of the usual colour, viz. a lightish red*. They 
are almost too hard to be scraped with a knife, but Feldspar 
varies much in hardness 3; the crystals in the Moor Stone on 
Westminster bridge stand above the rest of the stone, are 
consequently of a harder nature, and do not wear so fast. 
In other instances it is found decomposing, soft, and nearly 
powdery f. 
The primitive faces, or sides as it were, of those figured at 
the apex and base of the crystals, fracture smoothly and with 
facility., The other four break irregularly or roughish, The 
former generally show some sparkling illinitions, which are 
very apparent in some specimens, and serve to distinguish 
which of the terminal faces is the primitive one. 
* White or transparent Feldspar, being found at Adula, is called Adularia 
Moon Stone, Feldspath nacré.— Hazy, &c. 
+ This is often called Kaolin, and is frequently found in China manu- 
factories. 
