"2S4 Cross a,,, I Hilh hrnwl S (tn ,< i ' nf< r, sf ',/,</ Minerals 



According to the latest edition of Naumann-Zirkel's "Ele- 

 mente der Mineralogie" (Leipzig, 1881), phenacite has been 

 described from but four localities — two in the f'ral Mountains. 

 one in Lothringen, and one in Mexico. Dana* gives a second 

 locality in Mexico. The crystals described recently by 

 Webskyf being from an unknown source, the locality near 

 Pike's Peak seems to be the sixth authentic occurrence of this 

 rare mineral, and the first in the United States. 



A partly historical description of phenacite and its known 

 forms was'given by <h Seli<rmann in the " Neues Jahrbuch fur 

 Mineralogie " etc., 1880, I, 129. 



ZlECON. 



G. A. Konig has described and analyzed zircon from two 

 occurrences of the Pike's Peak district, in one case the mineral 

 being associated with astrophyllite,^: and in the other with 

 Amazon-stone. § In one of the instances we have to describe, 

 the zircon is intergrown with large crystals of flesh-colored 

 microline, in one of the localities above-mentioned, and is thus 

 analogous to the latter occurrence noticed by Konig. There 

 were many loose crystals in this cavity, but a few were found 

 penetrating or imbedded in the microline. The crystals 

 described by Konig showed both pyramid and prism, but the 

 prism is entirely lacking on all of our specimens. Some crys- 

 tals arc more than an inch in diameter, and these large ones 

 especially arc often mere aggregates of numerous small pyra- 

 mids grown together with a common crystal lographic orienta- 

 tion. The lateral edges of such crystals are often continuous. 

 but the terminations arc made up of many small pyramids. 

 Although the pyramid 1 is the only prominent form, one can 

 notice, on looking at the terminations in the right position, a 

 minute reflecting surface on each perfect apex. A closer 

 examination 'with the loupe shows it to correspond to the basis 

 0, but all observed surfaces are too small to admit of certain 

 determination. 



Near the Pike's Peak toll-road, about due west from Chey- 

 enne Mountain, a prospect tunnel, in following a vein-like mass 

 of white quartz in granite, has disclosed a number of interest- 

 color and contains only traces of galena and chalcopyrite. 

 Within litis ho.lv, however, is a second smaller vein consisting 

 likewise chiefly of while quartz, but carrying in it a number of 

 other miner;:!-, the most abundant of them bcinu zircon. The 



