BNDUCH.] CATALOGUE OF COLORADO MINERALS. 139 



AzuRiTE. — In the No-lS'ame, together with malachite, the result of de- 

 composition of fahlerz, Caribou ; in the Eosita mines in Hardscrab- 

 ble district ; in the mines around Fairplay and Idaho ; on Trail Creek ; 

 Crater Mountain ; in the mines of the Elk Mountain district, Mala- 

 chite lode. Bear Creek, Gendhemas lode, Tucker's Gulch. Generally 

 the azurite is regarded as " blossom rock " by the miners. If result- 

 ing from the decomposition of fahlerz it usually indicates silver-bear- 

 ing ore. No crystals of any size were observed, the largest scarcely 

 measuring 0.5 millimeter. Small, very brilliant crystals were found 

 on Kendall Mountain, near Ho wards ville. 



Barite. — In clear, yellow, tabular crystals in the Tenth Legion Mine, 

 at Empire ; colorless crystals in the Terrible, at Georgetown ; near 

 Canyon City, transparent crystals are found in the arenaceous shales of 

 that region. Crystals occur in the limestones near Fairplay ; on the 

 Apishpa Eiver, crystals with fine terminations are found. Barite 

 occurs also in Gilson Gulch, Georgetown ; Montezuma ; white, red, 

 and brown in Clear Creek Canon ; on station 17 of 1873, and on sta- 

 tion 46 of 1873. At the Eosita mines. 



Basanite.— >S'ee Quartz. 



Beryl. — On Bear Creek, Tiffany's Eanch ; Stone Dam, Jefferson County. 



BiOTiTE.— On Buffalo Peak and station 64 of 1873. Several of the 

 trachytes, more particularly the porphyritic, contain small crystals 

 of biotite. It is also found in some of the basalt. When decomposed 

 it becomes splendent brown, otherwise it is very dark green, brown, 

 or black. 



Bismuth. — French Gulch. 



BiSMUTHiNiTE. — In the Las Animas Mine, pseudomorphous. Dr. O. 

 Loew* mentions copper and iron as occurring in the bismuthinite of the 

 Ward district. Occurs in the Pittsburgh Mine, Clear Creek County. 



BiSMUTiTE. — From the Las Animas Mine, incrusting the preceding min- 

 eral. 



Bituminous Coal. — See Coal. 



BoRNTTE. — Found on Eio Dolores ; San Juan region ; at Copperville, 

 near Canon City. 



BouRNONiTE. — Terrible Mine, near Georgetown, in small crystals. 



Brucite. — On James Creek. 



Calamine. — Park County. 



Calaverite. — Associated with other tellurides in theEed Cloud. Good 

 crystals have been obtained from Sunshine district. Found in the 

 Keystone and Mountain Lion Mine, Boulder County. Geuth pub- 

 lishes an analysis of calaverite,t and obtains the following result: 



Per cent. 



Au 38.75 



Ag 3.05 



Te 57.32 



V2 O3 0.05 



FeO 0.30 



AlaOsMg. O, &c 0.55 



100. 00 



Calcite. — In small crystals, scalenohedra, at the Monte Cristo Mine, 

 Central ; Mount Vernon ; Bergen's ranch ; rhombohedral crystals ou 

 Cheyenne Mountain ; in the limestones of South Park ; in the car- 

 boniferous limestones near the Arkansas Eiver, lining cavities ; sca- 



* Explorations and Surveys West of tlie 100th Meridian, vol. iii, p. 636. 

 t Zeitschr. fur Kryst. und Min., P. Grotb, vol. ii. No. 1, p. 6, 1877. 



