known by the Name of Turquoise. 293 
a prunitive argillaceous schistus of a blueish gray or grayish 
black colour, which excludes all idea of petrifaction: in the 
same place graphic schistus and quartz are found: in the 
argillaceous schistus the turquoise is disseminated through 
it; it is the same with it in the quartz and graphie schistus. 
In order to remove every idea of the turquoise being re- 
garded as a malachite or green copper (kupfergriin), Meder 
has given the following character of it: 
Its colour is the grayish green of the celadon apple: when 
the turquoise begins to soften in the acids, it is decomposed, 
and assumes a mountain green colour: when entirely de 
composed it is of a yellowish greenish white, and even straw 
coloured. 
It is generally met with disseminated in small scattered 
fragments, and rarely in a large mass; it is dull interiorly ; 
its fracture is compact, the fragments indeterminate, with 
sharp edges, opake when it is decomposed, and more or 
less translucid at the edges; it becomes softer and softer 
according to the degrees of decomposition, and _ latterly 
becomes brittle *: its specific gravity, according to Kirwan, 
is from 2°500 to 2°908. 
The turquoise in the mass is sometimes mixed with earthy 
oxidulated copper (ziegelerx) of a brick red. 
M. Meder thinks, according to all these characters, that 
the turquoise ought to be placed between the opal and the 
apple-green chrysoprase, with which it seems to agree the 
most. 
Lastly, the celebrated Cuvier, in the Journal de Physique, 
tome lii. p. 263, thinks that the turquoises which are found 
near Simore in Languedoc, and near Trevoux, are eupre- 
ous teeth of an animal whrch resembles that found at the 
river Ohio, or the mammoth of the English and the Ame- 
ricans, the carnivorous elephant. 
M. de Reaumur is the only person who has given any 
details upon the mines of turquoise, and the nature of the 
substances found m them. 
%* The turquoises are not all of an equal hardness: this may be attributed 
to the difference of the osseous substances which serve as their base. The 
degree of pctrifuction of these bones ought also to have an influence upon 
their hardness. 
His 
