Reexamination of American Minerals. 247 
almost black. When seen by transmitted light, the color is dark 
hyacinth-red and translucent. The streak is “dark yellow. From 
the difficulty of obtaining any quantity of sufficient purity, noth- 
ing accurate can be stated with reference to its specific gravity 
and hardness ; and for the purpose of analysis, I was obliged to 
use material, which although containing pure crystals of the van- 
adate, was yet mixed with crystals of molybdate of lead and 
other impurities. 
The chemical analysis is an imperfect one, yet the best that can 
be made from the mineral as it has sgpnoes found. It is as follows: 
Vanadie acid, - - 1170 
sak east ac - - - +4 - 2014 wy oe 
Oxyd 0 : : : B01 
Oxy ot hon and manganese, i ‘ : é 64S 
Os ak. copper, - - - - - 1:13 
Oxy: Ppe : ; . ; . $4) 
Water, - - : Pea Z 2-94 
99:08 
If we subtract the amount of oxyd of lead requisite to form 
Wulfenite with the molybdic acid present, we have left 22-82 
per cent. which is combined with 11-7 of vanadic acid, making a 
compound corresponding to, Vanadic acid 66:1, oxyd of lead 
33-9= 100. 
This result is not considered precise ; it corresponds however, 
more nearly with the composition of Descloizite as given by Da- 
mour (P bt ¥=V Pb...70-7), than with Dechenite by Bergmann 
(Pb V=V 45:34 Pb 54:66). 
e composition of Descloizite cannot be considered as hav- 
ing been fairly made out, for Damour’s results are deduced, as 
mine have been, 3h a ey impure material, and may on future 
hi as yet been found only in small quantity at this mine, asso- 
ciated with oxyd of manganese and wulfenite, the crystals of 
this latter substance being more or less covered with minute crys- 
tals of the vanadate. 
52. Pyromorphite. 
There are several shades of color belonging to this mineral, a 
green so dark as to be almost black, olive-green, pea-green, leek- 
green, greenish yellow and all intermediate shades. It is a very 
abundant ore at the Wheatley Mine, and large quantities of it are 
smelted. Specimens of great beauty are found occurring in bo- 
tryoidal masses with columnar si a gi hexagonal 
a plumose 
