F. A, Genth—Contributions to Mineralogy. 313° 
Future investigations will be necessary to ascertain whether 
there really exists a tellurid of silver, or tellurid of silver and 
lead, which has the white color and cubical cleavage of the 
altaite. 
c. ? Native tellurium.—I have above already mentioned, that 
the specimen brought by Mr. Higgins contained minute specks 
of a mineral which may be native tellurium. The quantity 
which I have observed is microscopic. They have a grayish- 
white color. 
According to Kiistel, native tellurium occurs at the Stanis- 
laus mine. That these greyish-white specks might be native 
tellurium has been suggested by the results of the analysis of - 
the light washings from the last mentioned analysis. They 
contained 94:23 p.c..of quartz and other insoluble substances, 
but no gold, and 5°77 p.c. of tellurium minerals, showing the 
following composition: 
Ag, 30°75 requiring Te 18°23—48°98 p. c. true hessite 
26°94 16°66=43" = altaite. 
56; 42°31 742 « tellurium. 
100°00 34°89 
leaving a h-green resi : 
soda yolds: ga aan powder of metallic nickel. Dis- 
Solves in nitric acid with a green color, yields on evapora- 
__ hessite, altaite and possibly of native telluri 
‘Ing 22-22 p. c. of quartz and 326 p.c. of 
