Idaho History July 19, 2016

Antimony in Idaho Valley County 1919

Antimony Camp


Antimony Camp on Johnson creek near Yellow Pine. (photo by Local Color Photography February, 2016)

Chapter II (pages 49-52)

From “Tungsten, cinnabar, manganese, molybdenum, and tin deposits of Idaho”
University Of Idaho School Of Mines Bulletin No. 2
Moscow, Idaho Jan. 1919
By D. C. Livingston
With Notes on the Antimony Deposits By Francis A. Thomson
Cornell University Library TN 24.I2L78

Deposits of antimony have been known for several years on the southern rim of Yellow Pine Basin near the center of Valley County.

The basin itself is formed by the confluence of Profile Creek flowing in from the north, the East Fork of the South Fork of Salmon River flowing from the eastward, and Johnson Creek flowing in from the south. The antimony ore is found about four miles from the mouth of the last named stream and the same distance south of Yellow Pine post office.

The district lies about 15 miles west of Cinnabar (see p. 55), and the antimony and mercury ores are probably related genetically.

The properties are reached by wagon-road, some 60 miles in length from Cascade, a station on the Long Valley branch of the Oregon Short Line. This road leaves the road to Cinnabar camp at the crossing of Johnson Creek. For about half the distance the road is fair and for the other half decidedly bad, furthermore, several summits are crossed which are deeply covered with snow six months in the year. At the present time the district has neither telephone, telegraph nor mail service; there is a weekly stage and the stage driver carries mail if so disposed.

Freighting costs 3c per pound from the nearest railroad point, and winter transportation is precarious and subject to much interruption. A more feasible road-route could doubtless be found if road construction were justified.

Geology. The general geology is simple, the country rock being the biotite granite characteristic of the Central Idaho region. Dikes of pegmatite, aplite and complimentary basic dykes are in evidence, and there are the usual magmatic quartz veins usually goldbearing, in connection with which and with the pegmatite the antimony ore occurs, the whole occurrence being entirely regular and normal. There are places, however, in which the stibnite appears as patches or islands in the granite in a manner which suggests a direct replacement, such an occurrence is unique as far as the writer is aware and deserves further study as a problem in ore-genesis.

The antimony mineral is of course stibnite as has been stated, it is very clean and free from admixture of other sulphides. The sulphide ore reaches practically to the surface, there being nothing more than a mere skin of the oxides of antimony.

The Ore Deposits. It is convenient for purposes of discussion to divide the district into the east side and the west side respectively of Johnson Creek.

The east side deposits on which development work has been done, appear to consist essentially of two or perhaps three distinct quartz-stibnite veins. One of these striking north, is traceable for 4000 ft. in the course of which, as exposed in frequent cross-trenches, it shows from 6 to 18 in. of clean stibnite. The lowest exposure on this vein is 1700 ft. above Johnson Creek. Just beyond the point where this vein should cross over the ridge parallel to Johnson Creek and 2300 ft. above it, and on the eastern slope of the ridge is the most important exposure on the east side. Here, due possibly to the intersection of a system of linkage veins are several lenses of practically clean stibnite, the largest one of which has a maximum width of 5 ft., a length of 30 to 40 ft., and an undetermined depth, possibly 15 or 20 ft. The ore here shows both the quartz-stibnite vein type of deposition and an irregular replacement or segregation occurrence in the surrounding pegmatite-granite formation. This rather remarkable ore-shoot or concentration has been poorly developed and badly gutted by underhand stoping from a grass-root tunnel by previous operators, who are said to have shipped several cars of ore to Chicago from this point. The logical method of development here would be by an adit-tunnel further down the eastern slope.

As to the croppings of the continuous exposure on the western slope these can bo tapped by an adit-tunnei on the vein and fair depth will be gained. A short adit which, however, missed the vein at the portal and diverged from it as it progressed, has been started, but common sense development here would give valuable information and a depth of perhaps 20 to 25 ft. per 100 ft. driven would be gained.

Altogether the showing on this side of the creek is favorable and abundantly justifies vigorous development.

While on the east side the valley is quite flat and then rises by gentle slopes to the summit, on the west side the cliffs rise abruptly from a steep talus slope which reaches practically into the creek bed. Whether this cliff represents a faultscarp or merely defines a zone or rib of weather-resistant material, I am unable to say. The material composing this cliff has been designated quartzite, pending the examination of a thin section, the writer is inclined to classify it as aplite or alaskite, or possibly a silicified phase of the granite formation. In any event, the significant thing is, that distributed apparently sporadically both vertically and horizontally over the face of this cliff which is a mile long and 500 ft, high, there are patches and bunches of stibnite, and in the talus slope at the foot are great boulders of three or four tons, some of which contain at least 25 per cent of the same mineral.

No work has been done, and one of three explanations is possible, (a) that the face of the cliff represents one wall of a vein or dike in which the stibnite occurs in small, irregular shoots; (b) that there is a series of veins or dikes intersecting the face of the cliff and that the stibnite lies in these, and (c) that the stibnite lies in segregated bunches throughout the general rock-mass of the cliff. Subject, of course, to further data to be furnished by development, I am inclined to the last hypothesis, some confirmation of which is furnished by the fact that country-rock samples on the east side show over one-half per cent antimony due to small specks of stibnite visible under the microscope. It is conceivable that the entire mass of this great cliff may prove to be of sufficient grade to justify large scale mining followed by water concentration for which all natural facilities are at hand.

Sampling Results. The following assays and analyses on samples taken, are included rather as qualitative than as quantitative data. Some rather extravagant claims were made as to gold values in the stibnite; these are not substantiated by the results obtained.


Selected particles of high-grade were segregated from No. 1 to give an indication of what might be expected by concentration or segregation.

Results were as follows:

Antimony, 63.10 per cent; Arsenic, none; Lead, none; Sulphur, 25.50 per cent; Iron, 0.56 per cent; Insoluble, 2.7 per cent.

(Doubtless the balance of the sample consists mainly of the more soluble felspathic portion of the gangue.)

Present Operations. The east side deposits are held under lease from the Idaho Antimony Mining Co., by Frank Nowak, Inc., a concern which it is understood is controlled in Chicago. The present operators, for whom Mr. Frank Nowak is in charge on the ground have done a small amount of development work and have completed a “go-devil” road some three miles long to their ore-treatment plant. This plant is situated near the river and in an airline perhaps a mile from the east side workings. It consists of a Stroud disintegrator for crushing the ore, a small mechanically-rabbled flat-hearth dryer operated by a one horse-power engine, and a small liquation furnace. In addition the plant is equipped with a standard Wilfley table, the place of which in the flow-sheet was not clear to the writer. The plant is expected to have a capacity of one ton per day.

The west side deposits are owned by Mr. Albert Hennessy of Yellow Pine, who is holding them in the hope of their being developed by outside parties.

In conclusion, it is evident from the foregoing that the Yellow Pine antimony deposits are of exceptional purity and offer considerable promise if ever transportation becomes available. To market a metal worth only 5 to 10 cents a pound, however, under present conditions appears to the writer practically out of the question.

There is some disposition locally to regard the antimony deposits as necessarily superficial in nature and unlikely to extend more than a few hundred feet in depth. There seems no justification from any point of view for such a conclusion.

It is easily conceivable that the west side deposits may prove in time to be the more important, meanwhile the east side offers the greater promise to small operators, but of course far more development even on these is necessary, before definite conclusions as to the extent of these deposits can be drawn. Such development is in the writer’s opinion abundantly justified provided the product could be profitably marketed.

Antimony ore of similar character to the foregoing is reported at Cinnabar, also near Edwardsburg in the same county.

link to book: Cornell University Library
scanned Google book with images:

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[hat tip to SA]
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1937 Map

(snipped from Yellow Pine Quad)
source: Perry-Castañeda Library Map Collection Idaho Historical Topographic Maps
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By Francis A. Thomson.

Antimony is a silver-white, shining, brittle metal. It has a specific gravity of 6.8 and its atomic weight is 120. Its most no table characteristics are its fusibility, (melting point 630° C.) and the volatility of its oxide and sulphide.

Antimony is occasionally found native. Various oxides and oxysulphides of yellow to reddish color are frequently found in the outcrops of antimony deposits.

Stibnite, the sulphide (Antimony 71 per cent, Sulphur, 29 per cent) is practically the only mineral which is mined for its antimony. It is a soft, brittle, shining, lead-gray mineral which readily tarnishes to a bluish-black. It occurs frequently in long-bladed crystals or aggregates which are usually deeply grooved or striated lengthwise. Stibnite is easily fusible, thin splinters melting in an ordinary can dle flame. Heated on charcoal with the blowpipe, stibnite gives a dense white coating on the coal and yields fumes of sulphur dioxide.

There are many ores, particularly those of copper, lead and silver, which carry appreciable amounts of antimony, but none of them are regarded as antimony ores, although small quantities of antimony are recovered from them as a by-product of lead and copper smelting.

Antimonides or sulph-antimonides of nearly all the metals occur in nature, none except those of copper, lead and silver are of any economic significance.

The following statement of uses and production of antimony is taken from “Antimony in 1916” by Edson S. Baston.

Uses of Antimony

Metallic antimony unalloyed has few industrial uses. In the form of fine powder, known as “iron black,” it is used for producing the appearance of polished steel on articles made of papiermache or pottery. For these purposes it is precipitated by the action of metallic zinc on an acid solution of antimony salts. Antimony alloys readily with most heavy metals, the alloy being harder than the two pure metals and also in most cases, possessing the property of slight expansion on solidifying. Type metal is an alloy of antimony, lead, and tin; babbitt, antifriction, or bearing metal is usually an alloy of antimony, tin and copper. Britannia metal, also known as “white metal,” is an alloy of antimony, tin and copper, with some zinc and, rarely, small quantities of other metals. It is used in making cheap domestic tableware, teapots, spoons, etc. Antimony alloys find minor utilization in battery plates, toys, cable coverings, etc. Leadantimony alloy or hard lead is used in making acid resisting valves.

White antimony oxide, mainly the tetraoxide (Sb2O4) is used for making opaque white enamel and other sanitary ware. In this use antimony oxides compete with tin oxide. Antimony oxide, mainly trioxide, is used as a coloring agent in manufacture of glass, as it is more readily fusible than tetraoxide and does not impart opacity to the glass. Antimony oxides are further used as paint pigments.

The red sulphides of antimony are used in vulcanizing and color ing red rubber, and also as paint pigments. The natural antimony trisulphide, stibnite, enters into the composition of safety matches or the compound is put on the match box.

Antimonate of lead containing an excess of lead oxide, known as “Naples yellow,” is used in oil paints and in the glass and ceramic industries. The antimony salt, tartar emetic (double tartrate of antimony and potassium) and antimony fluoride are employed as mordants in dyeing. Tartar emetic and antimony trioxide are employed medicinally.

Antimonial lead carrying 12 to 13 per cent of antimony is employed in the manufacture of shrapnel bullets. Smaller quantities of liquated antimony sulphide are used in the primers of shells. For this last purpose it is claimed the material must carry less than 2 per cent of impurities insoluble in hydrochloric acid. Antimony sulphide as a powder is used in the charge of some shells to produce on explosion a dense white smoke which is of service in range finding.

U. S. Production

The production of antimony ores in the United States in 1916 according to the best information available, was about 4500 short tons, valued at $40,580. The metallic antimony content of this material was about 1770 short tons. The average tenor of the ore in metallic antimony was therefore about 40 per cent. The principal producing states in order of importance were Nevada, California, Alaska, Washington, Oregon, Idaho and Arkansas. Utah and Arizona produced insigficant amounts.

… In Idaho the production was all from Shoshone County, although prospects are known in Blaine, Custer and Idaho counties. The production in Shoshone County was mainly from Pine Creek, in the Yreka district.

pgs 45-47
source: “Tungsten, cinnabar, manganese, molybdenum, and tin deposits of Idaho” 1919

See also:
Link to Fern Creek Cinnabar District
Link to Valley County (Idaho) History Index

page updated Dec 10, 2020