called The Jeffersornte. 
-\-2 F which is very nearly that indicated by the results of 
the analysis, we have for the chemical formula. 
4 C a S i^ + 3 M 11 S i^ + ^ e S i^, which gives us 
Silex, - • « 20 atoms, containing 60 atoms oxygen. 
Lime, - , - 4 8 
Protoxide of Manganese, 3 6 
Peroxide of Iron, - 2 6 
Which proportions are so near those of the results of the 
analysis, that we may adopt them without hesitation. From this 
formula, we obtain the true composition of this mineral to be, 
4 at. Trisilicias Calcicus, 
7619.60 
S at. Trisilieias Manganesus, 
6313.23 
2 at. Trisilicias Ferrieus, 
5535.38 
1 atom new mineral, «. 
19468.21 
Or else, 
20 Silex, - - - . 
11928.40 
4 Lime, - - 
2848.24 
S Protoxide of Manganese, 
2734^71 
2 Peroxide of Iron, - 
1956.82 
19468.21 
Which reduced to 10000 parts, gives 
Silex, - - - 0.6125 containing Oxygen 3.0808750 30 
Lime, - - - 0.1463 
.4109567 
4 
Protoxide of Manganese, 0. 1404 
.3080376 
3 
Peroxide of Iron, - - 0.1005 
.3081330 
3 
0.9997 
This mineral will therefore present, in the new and expressive 
language of Mr Berzelius, 
4iC S mg for its mineralogical, and 
4 C a S i® + 3 M n S i® -f- 2 F e S i® for its chemical 
formula. 
According to Professor Mohs’ new and elegant mode of clas- 
sifying and describing minerals, this would form a new species, 
in his genus Augite Spar, and come immediately after the Py- 
ramido-prismatic Augite Spar (Pyroxene, Haiiy). On account 
of its many cleavages, I would propose to give it, as a specific 
name, the epithet of Polystome. It would therefore be thus de- 
signated : 
