THE MINERALS OF IDAHO 57 



entirely similar to the deposits of the Camas district, which may be 

 considered as the southwestern continuation of the same zone. 

 They are quite distinct from the lead-silver deposits of the Hailey 

 region. 



The Red Warrior district is represented by a number of specimens 

 in the National Museum, as follows: From the Golden Eagle Mine 

 (Cat. No. 65671, U.S.N.M.) coarse native gold in irregular flakes 

 in rusty quartz; from the Wide West mine bluish unoxidised quartz 

 (Cat. No. 65680, U.S.N.M.) containing flakes of pale gold in minute 

 cavities, quartz, with sparsely disseminated pyrite and sphalerite 

 (Cat. No. 14764, U.S.N.M.), and heavy masses of auriferous pyrite 

 and spongy limonite (Cat. No. 14765, U.S.N.M.). Ore from the 

 Victor mine (Cat. No. 14767, U.S.N.M.) consists of coarse comb 

 quartz which is slightly iron stained and that from the Avalanche 

 mine (Cat. No. 14766, U.S.N.M.) consists of bluish auriferous quartz. 



The Snake River placers have been mined in Blaine County at 

 Neely resulting in a small production of fine gold. The output was 

 187 ounces in 1904 and 258 ounces in 1905. 



BOISE COUNTY 



The Centerville (Idaho Basin) district is one of the most important 

 gold regions of the State. The production from the discovery of the 

 district to 1898 has been estimated at $44,651,800 of which about 

 $4,000,000 was from lode mines and the balance from placers. The 

 gold occurs in recent stream gravels and in terrace or bench gravels 

 at various levels along Grimes, Granite, Moore, and other creeks. 

 Some old stream channels now covered by basalt flows have been 

 mined but have not proven very rich. The highest terrace gravels 

 often contain rounded cobbles of gold-bearing quartz up to 30 cm. 

 in diameter. In a body of gravels immediately east of Idaho City 

 the gold is fairly coarse with a value of $16.50 an ounce before melting. 

 Much of it occurs on bedrock or "false bedrock," the latter being 

 the Payette formation of Tertiary lake sediments which carry a 

 little finely divided pale gold associated with monazite in some layers. 

 The heavy residues associated with the placer gold contain abundant 

 monazite in sharp crystals. Samples from several placers near 

 Centerville and Idaho City, show, in addition to the monazite and 

 the usual garnet, magnetite, ilmenite, etc., larger crystals of poly- 

 crase and samarskite, sharp crystals of columbite, and other minerals 

 as described under the separate headings. A sample of pan con- 

 centrate from the Leary and Brogan placer, Poncia tract, Centerville, 

 contains all of the above minerals and also heavy pebbles of bismuth 

 carbonate. A specimen of placer gold from near Centerville (Cat. 

 No. 55776, U.S.N.M.) consists of well worn flat flakes of gold 

 uniformly 1 mm. in diameter. Two nuggets from Bill Williams 

 54347— 2Gf 5 



