290 A. H. Chester— Mineralogical Notes. 
8. SCORODITE. 
This mineral is also found among the specimens from the 
Horn Silver Mine, and particularly in connection with the 
amorphous sulphate of lead so common there. It does not 
occur abundantly, but in very thin crystalline crusts of the 
characteristic pale green color. and also in amorphous layers 
which shade from yellow to dull brown. The mineral occurs 
in such thin layers, and so mixed with foreign matters, that a 
pure sample for analysis can hardly be obtained, but before the 
blowpipe it reacts for arsenic acid, iron and water, and behaves 
in all respects like scorodite. So few localities of this mineral 
have been found that this occurrence is thought worth a notice 
here. 
9. BISMUTITE. 
Some samples of a mineral from near Casher’s Valley, Jack- 
son Co., N. ©., sent here for identification, prove to be bismu- 
tite. It occurs in a narrow vein affording only small masses, 
the largest being about the size of a pigeon’s egg, assoviated 
with dark red or black garnet, white mica and quartz, and 
rarely black tourmaline, the bismutite forming the matrix of 
the other minerals. As usual it has various colors, the purest 
and most unaltered being light apple green, while some parts 
are dark gray. It shades from these colors through yellow and 
light gray to chalky white in the amorphous parts. It has a 
laminated structure, in some instances appearing almost col- 
umnar. The specific gravity of the purest is 7-4 to 75. 
Analysis of the mineral* gave results as follws: 
1 RO Mgnt, Oey ore ee sk 86°36 per cent. 
COLE RE PET nae ae eaipraaes Sse 7°79 33 
1a @ apne ring uae ye 202 « 
Insolubler22ce see ees Spe a USI SS) oe 
Tho Gallia Seated Se ce eae 99°80 
It was not easy to select material entirely free from gangue 
but this was not necessary, as the solution of the mineral in 
dilute nitric acid is complete, leaving a residue of mica and 
quartz only. Deducting this residue and calculating to one 
hundred per cent gives: 
IB Oe oe So ea 89°80 per cent. 
COR Sse fel 2.4 Vee Selo mem 
EL @ pate eet ek eo 2°10 ss 
The formula suggested is Bi,C,O,+2Bi,H,O,, requiring 
Bi,O, 89°31, CO, 840 and H,O 2:29, which agrees very 
* By Mr. F. I. Cairns. 
