ENDLICH.1 CATALOGUE OF COLOEADO MINERALS. 153 



ToEBERNiTE. — (TJranite.) Found by Captain Berthoud on Lyden 

 Creek.* Probably mostly decomposed. Found on Griffith Mountain, 

 Clear Creek County. 



Tourmaline. — In the quartz of Gunnell Hill, near Central ; on Eun- 

 ning Hill, at Black Hawk ; on Guy Hill, and at Kevada ; in quartz 

 north of the Arkansas Eiver. Crystals with both terminations at 

 Montgomery ; on Ealston Creek. All tourmaline of Colorado is either 

 black or dark brown. 



Tremolite. — Smith's Fork of the Gunnison Eiver. 



Tufa. — Calcareous. On Currant Creek ; Eoaring Fork ; Frying Pan. 

 At the mineral springs of White Earth, Wagon-Wheel Gap, Pagosa, 

 Animas, and in Uncompahgre Park. 



Turquoise. — Southern Colorado. (Doubtful.) 



Uraconite, — Wood lode, Leavenworth Gulch, near Nevada. 



Uraninite. — Occurs in large quantities, massive in the Wood lode, 

 Leavenworth Gulch, near Nevada. An analysis by Dr. O. Loewt fur- 

 nishes the following result : 



Uranoso-uranic acid 11.37 



Sulphides of iron and copper 45.81 



Gangue (quartz by difference) 42. 82 



Uranochalcite. — Wood lode, Leavenworth Gulch, near Nevada. 



Vesuvianite. — In large crystals of simple combinations on Mount 

 Italia. North of Arkansas Eiver, in the granite. 



Wayellite. — South Table Mountain, at Golden. 



Wheelerite. — Described by Dr. Oscar Loew.| This mineral, which 

 is quoted from New Mexico, probably also occurs in the coal of Col- 

 orado. It is a resin, related to amber. Its existence in each particu- 

 lar instance, however, can only be determined by analysis, on account 

 of its physical resemblance to other resins occurring in the same man- 

 ner. The analysis of Wheelerite by Loew furnishes : 



^ (1) (2) 



Per cent. Per cent. 



Carbon.... 73.07 72.87 



Hydrogen 7.95 7.88 



Oxygen..... 18.98 19.25 



WiLLEMiTE. — Jones's Mine, Central City. 



Wolframite. — Eeported from Southern Colorado. 



Wollastonite. — Occurs in small quantities in some of the limestones 



near Fair Play. 

 WuLFENiTE. — Is found in Park County ; at Gold Hill, Boulder County. 

 Xenotimitb. — Eeported from Cheyenne Mountain. 

 ZiNCiTE. — Jones's Mine, Central City. 

 Zircon. — Bear Eiver; Middle Park. In small crystals. Crystals of 



zircon are found in the feldspar of Pike's Peak. Dr. G. A. Koenig§ 



has furnished the following analysis : 



Per cent. 



SiO.2 28.00 



MgO 8.93 



(Fe2 03)Zr02 60.00 



H2O 3.47 



100. 40 



* Proc. Ac. Nat. Sci. Phil., Part II, 1875, p. 363. " 



t Rep. Expl. and Surv. West 100th Mer., vol. iii, p. 636. 



t Eep. Expl. and Surv. West 100th Merid., vol. iii, p. 630, and Am. Jour. Sci., vol. 

 xlii, p. 571. 

 § Proc. Ac. Nat. Sci. Phil., Part II, 1876, p. 156. 



