193 
TAB. CCXCVII. 
SILEX Quartzum. 
Crystallized Quartz. 
Div. 1. Crystallized. 
Whuenever we wish to contemplate the wonders of 
Nature, we shall find ample scope for our researches in 
every branch of the creation. But subjects which are 
chiefly confined to ceconomical inquiries do not so readily | 
arrest our attention, as those which occur less frequently ; 
and it is a grateful task, when opportunity offers, to in- 
dulge in admiration of the beautiful varieties that excite 
observations which might otherwise be lost or neglected. 
I am glad not to let the present object escape, as it is not 
only very remarkable, but also very mstructive, being no 
where mentioned before. The singular crystallization, $0 
conspicuous on the edzes or angles of the pyramids, has so 
extraordinary an appearance, that it could not fail of being 
noticed by the miner ; and its uniformity, over a much larger 
group than is figured, is a sign of its being originally extended 
very orderly, however the position of the crystals would 
seem to interrupt it. The parts of the faces between the 
edges are covered with innumerable eighteen-sided crystals 
in various positions, among which is scattered a large pro- 
portion of light-brown Pearlspar, giving a pretty relief to 
the whiter edges, which thus have a more star-like ap- 
pearance. 
The very curious modification of this crystal of Quartz, 
lately brought from Cornwall, being quite new to me, 
I could not but desire to have it shown. It often hap- 
pens that the crystals of Quartz give some item of this sort 
of modification. 
VOL. III. O 
