gallery.] natural history. (Minerals.) 67 
a specimen of which is added; — the quincite of Berthier, or red opal 
of Quincy, near Meudon in France, which, containing magnesia, is 
rather to be considered as a hydrous silicate of magnesia. 
In the two next Cases are placed the Silicates with one base. 
Case 25 contains the silicates of lime and some of the silicates of 
magnesia and of alumina. To the former belongs the table spar or 
wollastonite from Mount Vesuvius, Nagyag, &c., and the oxenite ; 
perhaps also the alumocalcite of Breithaupt, before considered as de- 
composed opal, from Eibenstock, Saxony. 
The silicates of magnesia comprehend several of the minerals placed 
by Werner in his talc genus: — steatite, the more interesting varieties of 
which are, that of yellowish green colour from Greenland, and that from 
Gopfersgriin in Franconia, with small crystals of other mineral substances, 
especially quartz, converted into, and forming part of the massive 
steatite ; variety called chalk of Brian^n ; — keffekil, or meerschaum, 
from Natolia, of which the well-known pipe-bowls are made, and that 
from Valecas in Spain ; — also a related substance, called keffekilliie 
by Dr. Fischer, who discovered it in the Crimea ; — the lithomarge , 
or steinmark, has been associated with steatite, although most of its 
varieties are silicates of alumina ; the more remarkable of which are, 
that of a reddish yellow colour in porphyry, from Rochlitz, and the 
fine purplish blue variety from Planitz, formerly called terra mira- 
culosa Saxonica, &c serpentine, the purer varieties of which (ge- 
nerally hydrates) are called noble serpentine : they constitute, in com- 
bination with primitive lime-stone, the verde antico and some other 
fine green marbles; among the varieties of the common serpentine, 
the best known are those from Baireuth and from Zoblitz in Saxony, 
where they are manufactured into vases and various other articles; 
serpentine with embedded garnets, magnetic iron-stone, asbest, &c. — 
the marmolite of Hoboken in New Jersey, and the nemalite , from the 
same locality, likewise belong to serpentine. — With these is placed the 
metalloid diallage or diallagite , more commonly called schiller spar , 
from the Hartz, &c. ; and, what appear to be varieties of the same, 
the bronzite and the xanthophyllite To the silicates of magnesia is 
likewise referred the olivine, which, in its purer state, is denominated 
chrysolite or peridot, and when protoxide of iron is predominant, 
has, by some, been called hyalosiderite ; — also the polyhdrite, and 
the anthosiderite ( Case 14.) 
Case 26. Silicate of zinc, called smithsonite (after the ingenious 
chemist who first distinguished its nature, and that of silicates in ge- 
neral), and also electric or siliceous calamine, the finest specimens of 
which are those from Siberia and Hungary; the variety called willemiie, 
from Aix-la-Chapelle. — Silicate of manganese, of which there are 
several varieties (some of them only mechanical mixtures of this silicate, 
of carbonate of manganese, and quartz), which have received particular 
names, such as allagite, rhodonite, &c. Silicate of cerium or cerite, from 
Bastnas, Sweden, — with which is provisionally placed the rose-coloured 
substance called thulite, found with blue idocrase in Tellemarken, Nor- 
way. — Silicate of iron, to which belong the hisingerite, sideroschizolite, 
chlorophceite, chloropal, stilpnomelane , gillingite,fayalite, and some other 
newly discovered mineral substances. — Silicate of copper, or siliceous 
malachite, also called chrysocolla and copper-green : to which may be re- 
