FIRST MINING EXPOSITION AT DENVER, COLORADO. 
85 
in this respect, be placed between Hessite and Nagyágite. It probably 
differs írom ours in its composition tvo. The rock is a veinquartzite, nearly 
pure Horestone. 
Specimens of telluric ores which are mixtures of diíferent telluric 
minerals were exhibited in great quantities. In somé cases it was possible 
to discern the species; in otliers however tlie mixture was so intimate a 
one, tbat this task proved unsuccessful. Nagyágit occurs with Hessite, 
Altaite with Syivanite etc. 
In Transylvania we alsó find tbe association of telluric ores : Sylva- 
nite with Nagyágite; Syivanite with Petzite, Krennerite etc.; Syivanite with 
beautiful crystals of Tetraedrite ; Nagyágite with very nice crystals of Bour- 
nonite etc. 
Besides the above-named species, the following telluric minerals 
known chiefly by the description of Genth (Philadelphia) must be men- 
tioned. 
7. Calaverite the Goldtelluride, which according to Genth is perhaps 
the same mineral, which the practical miner in Hungary was induced to 
discern under the name of «Gelbe Reiche, Gelberz, Gelb Sylvan», and which 
was called Bunsenine by Krenner after a newer Chemical analysis, a name 
subsequently changed by v. Rath intő Krennerite. The Krennerite is as a 
mineralogical speies better determined ther the Calaverite, because its 
cristalline form is known too, while the cristallization of the Calaverite 
could nőt yet be deciphered. 
8. The Tellurite as oxyde of Tellurium has been observed by Petz 
(1842) as accompanying the native Tellurium of Farebery; bút on the 
5 specimens of the Museum and 4 specimens of the university collection 
(Budapest) it is nőt to be found. Genth has observed it in the cavities of 
the american native Tellurium (Keystone-Smuggler-mine), or as an incru- 
station (John Jay-mine). 
The Ferrotellurite (Fe Te Or) and the Telluropryite, in which one part 
of the Sulfur seems to be replaced by Tellurium are nőt yet sufficiently 
well determined as new mineral species of Colorado. Tliey occur associated 
with native Tellurium and Tellurite (Keystone mine, Magnólia district). It 
is nőt impossible tliat the hungarian Tellurium specimens will furnish 
those combinations too, bút the accompanyig Pyrites has nőt yet been 
analysed. 
9. Coloradoite is the Quicksilvertelluride occurring very rarely in 
several mines of the Ballarat Sunshine and Magnólia districts, bút nőt 
known at all in Hungary. 
It is w'ortk mentioning that the Telluric minerals of Gold and Silver 
are to be found west of the Rocky Mountains, while on the east the telluric 
compound of Bismuth the Tetradymite occur at several points. We have a 
