316 F, A, Genth—Contributions to Mineralogy. 
The most rational conclusion under these circumstances is to 
consider these minerals mechanical mixtures of different species, 
such as native antimony, altaite and hessite, with a peculiar 
tellurid of gold, 
Starting from this supposition, I found, after deducting the 
admixtures, the ratio of gold and the remaining tellurium as 
follows : 
In L, = 1: 4:95 
K II, « 1: 4°24 
cas tees 
a 
The two last analyses, those of the massive bronze yellow min- 
eral, seem to prove that “ gelberz” is nothing else than an im- 
pure calaverite. 
"he analyses of the graphic tellurium, for which the formula 
AgTe,+AuTe, has been given, correspond better with the 
formula AgTe,+AuTe,, especially, if the exact ratio between 
gold and silver, which has been found, is taken as the basis of 
the calculation. Ratio of Au: Ag in I=1: 0°84, in II=1: 08. 
The latter would give the following composition, which agrees 
very well with the analysis : 
Au_. . 197°0 26°47 
o-sAg 86°4 1161 
7°2Te 460°8 61°92 
744°2 100°00 
wanger, contains minute quantities of a lead colored mineral, 
which contains tellurium, silver and a small quantity of lead, 
surrounding the gold. The quantity was too small for further 
Letre -—I have examined two varieties of tetrady- 
ute, one found in placer gold at Highland, Montana Terr., 
by Mr. Kleinschmidt (1), and the other from the Phenix 
Mine, Cabarrus Co., N.G. (II). I. The Montana mineral 
