154 GEOLOGICAL RECONNOISSANCE 
The water was determined by heating the mineral in a small glass 
retort, the neck of which was connected with a chloride of calcium tube. 
The experiment gave 11.808 per cent. of water; this deducted from the 
total loss by ignition gives the carbonic acid; hence, the composition is: 
Oxide: of 2inG« 6s tiaras ie ek ie ww eae eee 73.262 
"WA: o.6.4) ba a ies 5 aS aie Ee ee A ew Hie ea wees 11.808 
Carbonic acide seer sseecescceceescvcesvans 15.010 
100.080 
The only mineral known consisting of oxide of zinc, carbonic acid, 
and water, is Smithson’s “zinc-bloom,” for which the formula 
3 ZnO.CO?-|-3 HO has been constructed. This formula requires: * 
Found by Smithson. 
Oxide of zines ++ ++ -eeeeeeeees 71.28 69.38 
Carbonic acid --.-+-- tee eeees 12.89 13.50 
Water ocsceccccvceseccenece 15.83 15.10 
100.00 97.98 
Von Kobell § constructed for this mineral the formula 
3 [2 ZnO.CO?}-|-2 [ZnO.3HO], which does not agree with Smithson’s 
analysis, and which, therefore, cannot be considered as expressing the 
composition of zinc-bloom. But Von Kobell’s formula agrees very well 
with the analytical results obtained by me for the above-described mineral, 
which has to be considered a new species, or at least a new variety of 
zinc-bloom, and for which I propose the name of “ Marionite.” + 
In 100 Found * 
Se ye 
& 
8 Zn O 324.24 72.99 73.262 
3 CO? 66.00 14.86 15.010 
6 HO 54.00 * 12.15 11.808 
444,24 100.00 100.080 
Blende (sulphuret of zinc), occurs abundantly at Wood’s mine. It is 
mostly of dark brown color, and large crystals are frequently found 
cemented by irregular masses of impure smithsonite. In some specimens 
the blende presents a cellular appearance, as if acted upon by a dissoly- 
ing liquid; the cavities are generally coated with a layer of minutely crys- 
talline carbonate of zinc, of gray or reddish color. 
* y. Dana’s mineralogy, 4th ed. p. 460. 
§ v. Rammelsberg’s Handworterbuch, etc., vol. 2, p. 295. 
+ Want of material prevented a repetition of the analysis. 
