196 BULLETIN 42, UNITED STATES NATIONAL MUSEUM. 



(3) Crystalline sand, with rough, coarse, crystals. Oxford, Chester County, Penn- 

 sylvania. (65353.) 



(4) Crystalline sand, with considerable impurity. Carter's Mine, Madison County, 

 North Carolina. (56310.) 



(5) Coarse granular. Webster, Jackson County, North Carolina. (65428.) 



(6) Coarsely crystalline and foliated. Placer County, California. (65351.) 



(7) Granular. Del Norte County, California. (65349.) 



(8) Crystalline and impure. San Luis Obispo County, California. (66350.) 



BISMUTH. 

 Bismuth Ores. 



(!) Oxidized ore, contains 55 to 60 per cent, of metallic bismuth. Northern Spy 

 Mine, Juab County, Utah. (55341.) 



(2) Oxidized ore. Bismuth Mine, Granite District, Beaver County, Utah. (55342. 



ALLOYS. 



Precious Metal Alloys. 



In treating auriferous copper coutaining bismuth Mr. Richard Pearce 

 discovered some beautiful crystals of an alloy of gold and bismuth, and 

 in studying the matter has formed a very interesting series of crystal- 

 line alloys of the precious metals. 



(1) Ascicular crystals, brown-gray. Containing gold 69.94 per cent., silver 0.63 

 per cent., bismuth 29.43 per cent.-Auii Bis. (55975.) 



(2) The same alloy, copper-red in color. (55976. ) 



(3) The same alloy, oxidized below its melting point; greenish-yellow. (55977.) 



(4) Octahedral crystals, containing gold 69 per cent., silver 21 per cent. ; yellow. 

 (55978.) 



(5) Crystalline alloy, containing gold 62.164 per cent., silver 35.486 per cent., cop- 

 per and bismuth 2.350 per cent. ; bright yellow. (5.5979.) 



(6) Crystalline alloy, containing gold 65.21 per cent., silver 33.19 per cent,, copper 

 1.60 per cent. ; very bright yellow. (55980.) 



(7) Crystalline alloy, coutaining gold 58.51 per cent., silver 39.16 per cent., copper 

 2.33 per cent.=Au6Ag6; pale yellow. (55981.) 



(8) Crystalline alloy, containing gold 94.15 per cent., silver 4.43 per cent. ; reddish 

 yellow. (55982.) 



(9) Octahedral crystals, containing gold 61.52 per cent., copper 38.48 per cent. = 

 AuCu,; reddish. (55983.) 



(10) Octahedral crystals, containing gold 93.49 per cent., copper 6.51 per cent. ; red- 

 dish. (.55984.) 



(11) Crystals, containing gold 60.16 per cent., silver 21.21 per cent., copper 18.63 

 percent.; yellowish-gray. (55985.) 



(12) Crystals, liquated from melted bismuth, containing gold 59.06 per cent., silver 

 37.21 per cent., copper and bismuth 3.73 per cent. : yellow. (55986.) 



Brass. 



Brass is an alloy of copper and zinc in varying proportions, to which 

 at times other metals are added in small amounts to give certain cbar- 

 acters to the alloy. It is applied to a large variety of uses familiar to 



