NS TY 
On Minerals accompanying Chromic Iron. 333 
Genth has recently analyzed the same mineral from Lancaster 
Co., and given it the name of Rhodophyllite, with the formula 
3(RO Si0s)+2(R2Os, Si0s)+9(MgO HO) which agrees well 
with his analysis. Hermann’s recent analysis of the same min- 
eral from the Ural is unquestionably erroneous. 
Ido not therefore consider the true formula of Kammererite 
as absolutely determined, and since these hydrotalcose minerals 
Insensibly pass into each other, Dana has undoubtedly acted ju- 
diciously in placing Kammererite under the previously deter- 
mined Pyrosclerite, especially as they are both trimetric. : 
bronzite.—This mineral is repeatedly seen in the serpentine 
near Texas, half a mile west of the village, constituting large 
masses, which are highly crystalline, foliated and fibrous. A 
selected specimen from this locality yielded : 
Silica, , ‘ ’ . 55-451 
Alumina, , V1 
Magnesia, . 31-832 
Protoxyd of iron, . 9°603 
Protoxyd of manganese, 0-984 
98997 
: Although parts of the same mass were penetrated by chromic 
fon, yet neither chrome nor nickel have influenced the Bronzite. 
Its formula is RO, AlsOs-+14(3RO, 2SiOs), the first member is. 
‘vidently an impurity, and the last which is the true formula of 
the mineral, is that of Augite, and not that of Anthophyllite, as 
thas been generally called. It will be observed to agree closely 
With the Bronzite from Ultenthal, analyzed by Regnault (Dana’s 
Min. 3d ed., p. 269), but the mineral from Texas is not charac- 
letized by the usual metalloidal lustre of Bronzite. 
Emerald Nickel.—This mineral with its brilliant green color, 
Sottrasts strongly with the lustrous black of the chromic iron in 
Which it occurs, and with the purple or lilac hue of Kammere- 
nite. It either forms so thin a coating upon the chromic iron or 
ose minerals, or is so intimately and uniformly blended with 
the latter, that I have not been able to obtain a specimen suffi- 
“ently pure to determine its exact composition. The following 
ahalysis was made of small fragments selected with great care: 
*) +. Silica, " : . . 36'823 
Alumina and oxyd of iron, 6 
Magnesia, . ; 
‘ 16-579 
e, : . ‘ 3°839 
Oxyd of nickel, . . 30837 
Carbonic acid, , : sl 4363 
Water, ’ 8-551 
