156 MINERALOGY OF ST JOHN'S. 
various, light and dark grey, greenish-grey, green, blue, 
&c. It is translucent, or slightly translucent, on the edges, 
while the claystone is perfectly opaque. The compact fel- 
spar has a splintery conchoidal fracture ; the fracture of the 
claystone, on the other hand, is even, and always smooth. 
The compact felspar is more or less fine in the grain, and 
the splinters more or less large. The strata of the compact 
felspar, like those of the greenstone and claystone, are also 
at times columnar, the columns being composed of small 
round concentric balls, and very brittle. These balls are 
at times partially composed of hornstone. This mineral 
occurs also in the compact felspar, in thin beds, in veins, 
and in masses : its colour is green, its fracture smooth, con- 
choidal, it is slightly translucent on the edges, and is as 
hard as quartz. 
Claystone again succeeds the compact felspar, and the 
latter is again succeeded by the former, thus alternating 
for about eight or ten miles across the peninsula. The 
claystone always possesses a slaty structure, and soon de- 
cays. The soil over the greenstone and amygdaloid is rich 
and good, while over the claystone and compact felspar it 
is light and poor. 
