154 MONTANA : INDUSTRIAL RESOURCES 



Ot'CurreiU'e — Reported in Sanders county, on Prospect Creek, in l)lanket 

 lu'ds. some of which are three feet thick. Also contained in the grey copper ores 

 of the Butte ditsrict which run about 25 per cent antimony. This is not I)elng 

 recovered as a by-product. U. S. G. S. says antimony deposits in this state 

 have been worked only during high prices. 



BISMUTH 



Uses — In metallic form I'or making low-fusing alloys or cliche metals which 

 are used in automatic fire sprinklers, fuses for electric wiring, and solders. Some 

 of the salts have a smooth luictuous feel, and are used in face and toilet powders 

 and in medicinal preparations. Also employed to a small extent in making optical 

 glasses. 



Occurrence — "With the copper ores of the Butte district which tests made in 

 1911 showed carried 20 pounds bismuth to the ton. Investigator reported not 

 worth saving at $:>j a ton. but U. S. G. S. ctmfident process will be evolved for 

 isolating bismuth from flue dust as rich as that derived from Butte ores. 



C.\DMIUM 



Uses — Chiefly used as an alloy in materials requiring low melting points, such 

 as sprinkler system heads, automatic releases on fire doors, also as alloy in cliche 

 metal for stereotype plates, in silver plating and dental amalgam. In recent ex- 

 periments used to replace tin in sohhn's and in bronzes, which would open a wide 

 field to it. Reported to be a better rust preventive than nickel. 



Occurrence — Reco\-ered as a by-product of the zinc ores from Butte district in 

 a ratio of one part to 5()0 parts of zinc at the electrolytic zinc plant of the 

 A. C. M. Co. in Great Falls. Precipitated electrolytically on aluminum plates, the 

 product being 99.97 per cent pure. 



CHKOMTTE 



Uses — It is the chief ore of the metal chromium which is smelted in the 

 electric furnace to produce the alloy of iron and chromium called ferrochrome, 

 used in making chrome steel, another alloy. r<Mniirkable for its hardness. Fuses 

 or melts only at a ver.y high temperature and used as refractor.v material for lin- 

 ing furnaces. Chemical compounds of chromium are used in making pigments, 

 dyes and mordants in oxidizing, bleaching and tanning. 



Occurrence — Two deposits of chromite are reported in Montana by the 

 U. S. G. S., one. 10 miles southwest of Red Lodge, between Rock Creek and 

 West Fork of Rock Creek (Carbon county), and the other in Stillwater and 

 Sweet Grass counties. This l;itter deposit starts on Boulder River in Sweet 

 Grass county, 10 miles south of ^IcLeod, and extends in a general direction south 

 of east for 27 miles, to Fishtail Creek, in Stillwater coiuity. It is not only one 

 of the largest deposits in the I'nited States, but the T'. S. G. S. says, "the 

 form of occiu'rence of the chromite in this belt is radically different from 

 that of deposits farther west, in California and Oregon, and that there is much 

 stronger reason for counting on continuity in depth here than there". 



Estimates of the available tonnage have been made for onl.v 19.000 feet in a 

 total length of 27 miles. This estimate is ;j.")O.0eH> tons to a depth of 100 feet, but 

 the U. S. G. S. says without doubt the ore goes beyond that depth to a con- 

 siderable distance, possibly 1.000 feet. Seven samples returned assays averaging 

 36.5 per cent of chromic oxide with an iron content of 1(5 to 19 per cent. The 

 assays were taken in the main, or high grade ore body which averages 12 inches 

 to two feet thick. The mixed ore. which averages four feet in width, assays 5 

 to 25 per cent chromic oxide. Concentrating tests, it is reported, show the 

 mixed ore will concentrate to a 39.S per cent chromic oxide ore with a 53 per 

 cent saving of the chromite. The assays made of this chromite ore indicate it 



