Dr. Genth’s Contributions to Mineralogy. 19 
alliaceous odor, and fuses with intumescence to an iron black, 
slightly magnetic globule, covering the charcoal with white in- 
crustations. With fluxes it gives the reactions of copper and 
iron, 
A preliminary analysis, made by dissolving the mineral in aqua 
regia, gave Mr. Wm. J. Taylor the following results : 
4 40°64 pr. cent. 
Sitter, oe 
Gold, 2 ‘ : : trace 
Zine, ‘ : ‘ : , 3°39 
irom. 5 F . : : 4:24 
Antimony, . ° : : ° 510 
Arsenic, Fr . = i - 16°99 
Sulphur, . . . ; diesen 28:46 
Quartz, : x Si 1-24 
~t is associated with quartz and auriferous iron pyrites 
. From Geo. Luderick’s farm, about 14 miles N. E. ‘of Con- 
pork (abies county, N.C.—The only imperfect crystal which 
I found appears to be a combination of = 2s" -@O; it is gen- 
erally found massive ; its color is between dark lead gray and iron 
black ; streak iron black, somewhat brownish ; fracture uneven, 
subconchoidal ; brittle. 
B.B. decrepitates slightly ; in an open tube disengages sulphur- 
ous acid and gives a snblimate of arsenious acid; on charcoal it 
emits fumes of an alliaceous order, and covers it with white in- 
crustations ; it fuses into a magnetic globule and gives with 
fluxes the reactions of copper and iron. It is found in quartz, 
pes tg with copper pyrites, iron pyrites, brown hematite and 
scor 
10. Geokronite. (?) 
I received this mineral amongst others from Tinder’s Gold 
Mine, Louisa county, Va. 
t occurs in small irregular masses of a crystalline structure, 
With distinct. ern in one direction ; lustre metallic ; color 
aeyi Ser ines ; Sp. on (at 16° Cels.) 6-393. 
fames of. teroxyd of antimony, soueriug it with white incrus- 
tations, having a Baas centre of oxyd of lead; further reduced 
Yields a small globule of silver ; in an open tube it gives off snl- 
phurous acid and a’ white sublimate of teroxyd of antimony and 
A cae paces wed th bout 16 t 
i ho that it contains abou per cent. 
of ee 60 per cent. of lead, and 0-25 per cent. of silver. 
Associate eh iron Sd galena, aud blende. 
