14 
SALOON. 
Nat= Hist. 
Case 2. The diamond, though combustible, is 
by common consent considered as the first of 
precious stones: among the specimens selected to 
exemplify its crystalline forms, are the primitive 
regular octahedron j the same with solid angles 
truncated ; with edges truncated, forming the 
passage into the rhomboidal dodecahedron; 
varieties of the latter, giving rise to the six-sided 
prismatic and the tetrahedral forms 5 cubes with 
truncated and bevilled edges; various hemitropic 
crystals or macles of diamonds, he. With these 
are also placed specimens of the alluvial rocks 
in which the diamonds occur in the East Indies 
and in Brasil.— Zircon: to which belong the com¬ 
mon jargon of various colours, and the orange- 
coloured, considered by some as the irnehyacinth^ 
from Auvergne, Chili,&c.; also the variety called 
zirconite, from Friedrichsvarn in Norway, kn- 
bedded in syenite, a rock composed of feldspar 
and hornblende .—Corundum : which compre¬ 
hends the precious stones commonly called ori¬ 
ental gems (thesapphire,ruby,oriental amethyst, 
oriental topaz, oriental emerald), of the crystal¬ 
line forms of which the principal modifications 
are here deposited; and the common or imperfect 
corundum from Bengal, Mysore, China (the dia- 
mant-spath of Werner), Lapland, Piedmont, &c. 
—As appendix to these are added, \h.eJib 7 oUte 
(bournonite of Lucas), one of the concomitant 
substances of common corundum; and the emery 
which owes its hardness and consequent useful¬ 
ness 
