22 
SALOON. 
Nat. Hist. 
eties of which are found in Siberia ; the variously- 
tinted common jasper ; the agatejasper , found only 
in agate veins; the porcelain jasper, which is pro¬ 
duced by the agency of subterraneous fire. Also 
the substances constituting the obsidian tribe, such 
as the pitch-stone , which is often confounded with 
semi-opal;—the pearl-stone , so called from its co¬ 
lour 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- 
chotsk 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 
pelioma , and dickroite from its exhibiting two dif¬ 
ferent colours when viewed in different positions. 
{Case 10.) This case contains zeolitic substances, 
viz. several varieties of scolicite and of mesotype, 
among the specimens of which may be particu¬ 
larized those with perfect prismatic-acicular crystals 
( needle-stone of Werner); the delicately fibrous va¬ 
rieties ; the red compact variety, by some called cro- 
palite, &c.—The natrolite of Klaproth, of which a 
few specimens are added, is by some considered as 
a variety of mesotype.— Stilbite, mostly crystallized: 
among the coloured varieties is the red from Fassatt 
(Fassait).— Apophyllitc, some varieties of which 
have been mistaken for mesotype and stilbite.— 
Analcime, 
