34 
SALOON. 
Nat. Hist. 
Case 27. Strontian salts ; carbonate of siror,?- 
tian, also called strontianite, in prismatic and 
acicular crystals, which latter have sometimes 
been mistaken for arragonite.—Among: the sul- 
phates of strontian (celestine of Werner) the more 
remarkable specimens are, the splendid groups 
of limpid prismatic crystals from La Catolica in 
Sicily; the acicular variety in the hollows of 
compactsulphate of strontian, from Montmartre; 
the same in fissures of flint; the radiated and 
fibrous celestine, &c. 
T.heremainder of this case is occupiedbysome 
other saline stony substances, viz . carbonate of 
magnesia, called also pure magnesia, and mag¬ 
nesite. Borate of magnesia, or boracite , in sepa¬ 
rate crystals, and the same imbedded in gypsum; 
—hydrargillite or wajvellite , which may be consi¬ 
dered as a phosphate of alumina ; azurite and 
blue spar (Werner’s lazulit and blauspath), which 
appear tobe phosphatesof alumina, magnesia, and 
silica;— aluminite , a subsulphate of alumina, from 
Sussex, and from Halle in the territory of Mag¬ 
deburg, which was formerly mistaken by some 
for pure alumina, by others for a hydrate of alu¬ 
mina with mechanically admixed sulphate of 
lime: it must not be confounded with alum-stone 
(alunite of French mineralogists), which, accord¬ 
ing to Cordier, is a hydrate of alumina with an¬ 
hydrous sulphates of alumina and potassa. Fluate 
of soda and alumina, or cryolite (found only in 
West Greenland), pure and intermixed with 
brown 
