338 



BULLETIN 131, UNITED STATES NATIONAL MUSEUM 



CUSTER COUNTY 



In the Alder Creek district a little calamine occurs as acicular 

 crystals set on a base of smithsonite in the Champion group prospect 

 south-southeast of the Empire mine and at an elevation of 8,000 

 feet, south of Cliff Creek. 62 It is very rare here. A very few minute 

 bladelike crystals of colorless calamine occur with the aurichalcite 

 described elsewhere in this bulletin, in a specimen from three sets 

 above the No. 4 level of the Empire mine at Mackay. 



■ro- 



103 104 105 106 107 



Figs. 103-107.— Calamine crystals. 103, 104, Pittsbubq-Idaho mine, Lemhi County. 105, Pacific 

 mine, Custer County. 106, Red Bird mine, Custer County. 107, Beardsley mine, Custer 

 County 



In Northwestern Custer County calamine occurs as bundles of 

 clear white columnar crystals protruding from the walls of small 

 cavities in the oxidized lead-silver ores of the Bay Horse district, 

 particularly the Red Bird, Beardsley, River View, and Pacific mines. 63 

 A specimen from the River View mine consists of radiated-compact 

 white calamine making up a cellular mass. 



Specimens from the Red Bird mine consist of botryoidal masses 

 having a limonite-stained drusy surface made up of minute calamine 

 crystals on which rest a few tiny white cubes of fluorite. The cala- 

 mine crystals are vertically elongated and flattened parallel to the 



M J. B. Umpleby U. S. Geol. Survey, Prof. Paper 97, p. 50, 1917. 

 « J. B. Umpleby. U. S. Geol. Survey, Bull. 539, p. 52, 1913. 



