21 
different varieties or subspecies of jasper, such as saloon. 
they are enumerated by Werner, viz. the globu- N;VT - HlST< 
lar or Egyptian jasper, found chiefly near Cairo, 
in rounded pieces, which appear not to owe their 
form to roiling, but to be original and produced 
by infiltration; the ribbon jasper, or striped jas¬ 
per, the finest varieties of which are found in Si¬ 
beria; the variously-tinted common jasper; the 
agate jasper, found only in agate veins; the porce¬ 
lain jasper, which is produced by the action of 
subterraneous fire on clay-slate. Also the sub¬ 
stances constituting the obsidian tribe, such as the 
pitch-stone, which is often confounded with semi¬ 
opal ;—the pearl-stone, so called from its colour 
and the small globular concretions of which it is 
composed;—the obsidian , a remarkable variety 
of which is that found in globular pieces, at Oc- 
ehotsk in Siberia,near the small river Marekanka, 
from which it has obtained the name of mareka- 
nite; pumice, which is not in all cases of volcanic 
origin. Near these substances are placed some 
specimens of the mineral called by some iolite 
and peiioma, and dickroiie from its exhibiting two 
different colours when viewed in different posi¬ 
tions ; together with the blue quartz from Ora- 
yervi in Finland, called also steinheilite . 
Case 10. This case contains zeolitic sub¬ 
stances, viz. several varieties of scolicite and of 
mesotype, among the specimens of which may be 
particularized those with perfect prismatic-acicu- 
larcrystals(n^/e-5/owcofWerner); thedelicately 
fibrous 
