Mineralogy and Petrography. 1023 
Montana ——Descloizite (ramirite), from San Luis Potosi, Mexico, 
yielded Professor Genth* on analysis the figures,— 
> fo CiO ZO AsO, V0; P,O; Loss on ignition 
F352 6.58 12.70 3.63 19.99 33 2.62 
_ isregarded by Rammelsberg as being represented by the ormula 
_ pure material, with this result: 
ee Ag Pb Bi Cu Te S 
E> 38.59 7-24 25.05 0.21 17.43 8.24 
which, after deducting the impurities, would give, as the compo- 
_ Sition of tapalpite, 
e A Bi Te S 
. 46.09 24.99 21.67 7-25 
_ Corresponding to a normal sulpho-telluro salt of silver and bis- 
a muth——_In he i i 
orro County, New Mexico; and /usingerite pseudomorphs after 
te—This min- 
has for some time been regarded as a basic carbonate of 
muth, but its composition has not until very recently been 
SO, Silicates co, H,O 
0.34 0.08 8.03 0.47 
responding to the formula Bi,O, CO, = (BiO),COs-—— Cree 
= €—Messrs, Chester and Cairns’ have recently published an 
sis of the bluish-gray fibrous crocidolite from Beacon Pole 
near Cumberland, Rhode Island, with the result (as the 
^ of two analyses) : HO 
Fe,0, FeO M Na,O 
oo 21.22 4 6% 1.37? 
. Lig i. p- 36 I. 
= Amer. Jour SGT October, 1887, P- 27% 
