BOTUCH.] GEOLOGY MINERALOGICAL NOTES. 355 



a short time, the assay becomes highly magnetic, indicating the presence 

 of a considerable quantity of iron. Nitro-muriatic acid decomposes the 

 mineral. 



Subject to the same conditions as No. 1, I shall, if the results are 

 subsequently verified, propose for this mineral the name of Schirmerite, 

 dedicated to Prof. J. F. L. Scbirmer, of Denver, who kindly supplied 

 me with specimens from his rich store. 



NATIVE TELLURIUM. 



Hexagonal j occurring massive and in small crystals ; lateral cleavage, 

 perfect ; form, columnar masses in the accompanying white quartz. 



Hardness, 2 to 2.5 ; specific gravity, 5.802, which is lower than that 

 given for tellurium, 6.1 to 6.3 ; but may be explained by the fact that 

 the metal and quartz could be separated but imperfectly. Structure, * 

 lamellar ; color, tin- white to light steel-gray ; luster, splendent j streak, 

 submetallic, light-gray to gray. 



In the open tube it gives off white fumes of tellurous acid and a strong 

 selenium odor. Before the blow-pipe, on charcoal, melts readily, coat- 

 ing the latter white in the oxygen-flame ; black or very dark-gray in the 

 red flame. Treating for some time with the red flame on charcoal and 

 moistening the black coating with concentrated sulphuric acid, the 

 coating will turn a bright carmine upon warming gently. Held into a 

 steady oxygen-flame it colors it blue, with the edges tinged bright green. 

 Bismuth produces a slight yellowish tinge on charcoal near the assay. In 

 the closed tube the characteristic red deposit occasioned by selenium 

 is found. 



As stated above, this tellurium is intimately associated with quartz, 

 which composes 52 per cent, of the entire mass. An analysis, in which 

 the constituents other than tellurium were determined approximately, 

 gave the following result : 



Te, Se, Fe, Bi, An, Ag. 

 90.85, approximate, trace, trace. 



Having obtained more material, a full analysis will be given. It is not 

 so pure as the tellurium from Transylvania, which yielded from 92 to 97 

 per cent, of the metal. 



CATALOGUE OF THE MINERALS OF COLORADO TERRITORY. 



The following is a list of the minerals found in the Territory of Col- 

 orado, give^ as completely as possible up to date. In compiling it, the 

 observations of Professor Schirmer, from Denver, Mr. J. A. Smith, ter- 

 ritorial geologist, Mr. von Schulz, E. M., Mr. Peters, E. M., Mr. Frazer, 

 E. M., Dr. A. 0. Peale, Mr. Marvin, and myself have been used. The 

 single initial after the enumeration of each locality or series of localities 

 gives the name of one of the above-mentioned gentlemen by whom the 

 mineral was collected or observed at that locality. Mr. Smith's Cata- 

 logue of the Principal Minerals of Colorado afforded much valuable in- 

 formation. The comparatively meager representation of mineral species 

 in a country so richly endowed with mining-lands as Colorado is is per- 

 ceptible at a glance. Very little definite and applicable knowledge has 

 thus far been gained relative to the distribution of minerals and ores 

 throughout the world, and every catalogue, however small, if only ac- 

 curate, adds its share to the further development of that knowledge. 



