148 GEOLOGICAL RECONNOISSANCE 
represent the composition of a fair average-specimen of the whole of the 
ore brought out from this mine. The ore No. 1, contains, occasionally, 
cavities in which small yellow crystals of blende (sulphuret of zinc) are 
found. 
Although of comparatively rare occurrence at this locality, large 
crystals of blende are occasionally met with, sometimes imbedded in dolo- 
mite and surrounded by masses of flesh-colored, crystallized smithsonite, 
(carbonate of zinc), and pearlspar. Crystals of smithsonite are abundant; 
they are either found in the small veins traversing the dolomite (No. 32), 
or forming the outer layer of irregular masses of ore, imbedded in red 
clay; the crystals are of pale yellow, pale red, or flesh-color, rough on the 
exterior, frequently possessing curved faces. A few hand-specimens pre- 
sented the appearance of a brecciated rock; here, angular fragments of a 
light reddish-gray, very. close-textured dolomite (?) of splintery fracture, 
were imbedded in a matrix of greenish-gray, coarser grained dolomite, 
intermixed with flesh-colored crystals of smithsonite. 
The great mass of the ore occurs imbedded in red, feruginous clay, in 
more or less rounded, irregular pieces. These pieces frequently consist 
of three distinct layers: the outer one is formed of well-developed crys- 
tals of pure smithsonite; then follows a layer of amorphous smithsonite, 
possessing the physical properties of the above described ore, No. 1, which 
passes gradually into a very soft amorphous mass of the composition 
given in No. 2, and which is nothing but the same mineral constituting 
the second layer, intermixed with some clay and other impurities. Its 
color is from cream-color to brownish-yellow; it is easily scraped with a 
knife, yielding a cream-colored powder. 
No. 1. Massive, amorphous, carbonate of zinc. 
Composition dried at 230 deg. F: 
Clay, and silicia «++ sees eee ee eae teeeeeeee 18,805 
Carbonate of ZiInGs + eset eee ree erence arenes 75.474 
6 & JME) oer ee ecw ec er erence eeens 0.364 
a  MAQNESIA + see e eve ners eceene trace 
Peroxide of iron, and alumina-......+.+.6+. 1.771 
Water, and losss +s sees eee eee e een eeees rete 3.586 
100.000 
The air-dried ore lost 0.69 per cent. of moisture at 230 deg. F. 
The carbonic acid in the carbonates of zinc and lime amounts to 26.685 
per cent.; a separate experiment, on treating the pulverized mineral with 
hydrochloric acid in a carbonic acid apparatus, gave 26.881 per cent. 
Some of the iron was probably in the state of proto-carbonate. 
