1>R. J. SZABÓ 
84 
Boulder Co.). In tbis state it shows remarkably well how rich in Gold 
an őre may be, which appears at first Bight to contain, only somé 
grey spots. By high temperature the Gold is forced out of tke cavities, and 
expands over tlio surface of the quartz, forming globules or crystallized 
masses, in a similar way as that, in which the phenomenon known under 
the germán term «das Spratzen des Silbers» takes piacé on tho surface of 
the Silver-cake after having been freed from lead by cupellation. 
4. Hessitc (Síidé mine), this silver telluride occurs in nearly tin wliite 
lamellar masses, accomj)anied by Pyrite and crystals of secundary quartz 
of the same age. The rock is highly quartzose in a grey calcedonic state, 
bút containing grains of felspar, which are almost entirely converted intő 
white kaolin in a manner that the kind of rock is nőt determinable macros- 
copicallv. 
Professor Keenner. keeper of the mineralogical department in the 
National Museum (Budapest) gave a description (1879) of the Silvertellu- 
ride of Botes (half way between Vöröspatak and Zalathna in Transylvania, 
S. E. of Hungary) which is very well crystallised, the crystallisation of 
which beeing isometric, differs from Hessite (rhombic). About 10 good 
specimens have been secured fór the collection of the Museum at Buda¬ 
pest. An aggregate of fine crystals, having the height of 14, and the width 
of 7 centm. it the most splendid specimen of that locality, and has been 
presented to it by Mr. Semsey. Becke (Vienna) found a triclinic form with 
isometric habitus, bút according to prof. Krenner probably on less perfect 
crystals than those, which were at his disposal. 
The specimen of the Silvertelluride of Botes and of Altai (Savodinsko 
mine) have the same colour and lustre, the Colorado specimens, seem to 
differ a little, they are somewhat brighter. 
In the mines of the Botes (Jacob and Anne mine) this is the only 
telluric őre known till now. On the surface of the crystals native Gold is 
sometimes met with, bút as associated minerals Pyrite Chalcopyrite and 
secondary Adularia are to be observed. 
5. Petzite the Silvergold telluride of Nagyág was determined at Buda¬ 
pest (1843) by the able chemist Petz, who followed the method, and used 
the apparátus of Plattner, in the management of which he was a master. 
It is a Hessite in which a part of the Silver is replaced by Gold. In Ame¬ 
rica this is often met with, while in Transylvania it is as a distinct species 
nőt very well distinguishable from the Sylvanite, bút is included in the 
generál name of this latter mineral, the external characters as well as 
the mode of occurrence beyng nearly the same. 
6. Nagyágite (Inter Óceán mine). The mineral given to me under 
this name has the lamellar structure of the lead goldtelluride of Nagyág, 
bút differs from this in colour, being considerably brighter, so that it may 
