20 
SALOON. 
Nat. Hist, 
red dendritic and other figures, vulgarly called mo 
cha stones; varieties with white, brown, and black, 
straight or curved lines: onyx, sardonyx, &c. 
(Case 7.) Caleedonic substances continued. 
Among these are various specimens of the red and 
yellowish varieties of caicedony, called cornelian i 
striped carnelians, &e.— Heliotrope, an intimate 
mixture of caicedony and green earth, which, when 
containing disseminated particles of red jasper, is 
commonly termed blood-stone.—The beautiful and 
much esteemed variety of caicedony, called chryso- 
prase: it has hitherto been only found at Kosenriitz 
in Silesia, accompanied by a siliceous earthy sub¬ 
stance called pimelite, which, like the clirysoprase, 
owes its green colour to oxide of nickel.—By way 
of appendix to the caleedonic substances, are added 
a few specimens of the less compound varieties of 
agates, in which common caicedony, carnelian, and 
heliotrope respectively form the predominant ingre¬ 
dients. (See also the table-cases,RoomI.)—Of flint, 
a well known mineral substance, several interesting 
varieties are deposited in this case. 
(Case 8.) contains principally opaline substances, 
viz. specimens of the noble opal, which owes its 
beautiful play of colours to a multiplicity of imper¬ 
ceptible fissures in its interior; the Mexican sun 
or fire opal; the common opal, a translucent white 
variety of which, appearing yellow or red when held 
between the eye and the light, is called girasol; the 
semi-opal. 
