1 25 
tome or cross stone, divided into baryte-harmotome 
and potass-harmotome, to which latter are to be referred 
the Vesuvian minerals called zeagonite , gismondine , 
abrazite, and also the philipsite. 
The remainder of this Case is occupied by species 
of the feldspar family.— Common feldspar , variously 
crystallized and massive: among the specimens here 
deposited may be specified—the fine green variety 
from Siberia, called amazon stone; the beautiful large 
crystals from Baveno; feldspar with embedded crystals 
and fragments of quartz (graphic stone, graphic gra¬ 
nite), from Siberia, &c.;— Labrador feldspar (also 
called opalescent feldspar, being remarkable for its 
beautiful play of colours), chiefly from the coast of 
Labrador and from the transition syenite of Laurwig 
in Norway ;~-adularia or naker feldspar , principally 
found on Mount St. Gothard, but not in the valley of 
Adula from which its name is derived: the fine va¬ 
riety from Ceylon, when cut en cabochon, is called 
moon-stone ; and a yellow naker feldspar with reddish 
dots has obtained the name of sun stone, which is also 
sometimes given to the beautiful avanturino variety of 
common feldspar placed in this glass case. 
Case 30. Feldspathic substances continued :— ice - 
spar and sanidine or glassy feldspar, both nearly allied 
to common feldspar; cleavelandite or albite, the finest 
specimens of which are those from Dauphine and Si¬ 
beria, and pericline , united by some mineralogists with 
the preceding species, from St. Gothard, Tyrol, &c.; — 
anorthite from Vesuvius;— oligoclase , also called na- 
tron-spodumen—together with some other species se¬ 
parated, perhaps unnecessarily, from common feldspar 
and cleavelandite;— leucite or amphigene, chiefly from 
Vesuvius, in separate crystals of various sizes and de¬ 
grees of transparency, massive, embedded in pyroxenic 
and other lavas ;— triphane or spodumen and petalite , 
substances in which lithia, or the oxide of lithium, was 
first discovered by Arfvedson. 
Case 31. This Case contains : nepheline , from 
Mount 
LONG 
GALLERY. 
Nat. Hist. 
