TESTS FOR TUNGSTEN.

When the mineral to be tested is readily decomposed by boiling with hydrochloric acid, an insoluble canary-yellow tungstic oxide, WO3, will be obtained if the mineral contains tungsten. If a little granulated tin is added to the solution and the boiling is continued, a blue color is obtained, which finally changes to brown by further boiling. If, however, the tungsten mineral is insoluble or not easily soluble in boiling hydrochloric acid, as in the case of the mineral wolframite, the finely powdered mineral should be mixed with six times its volume of sodium carbonate, and the mixture be made into a paste with water and fused. By pulverizing the fused mass the sodium tungstate formed during the fusion is readily dissolved in a test tube with a little water. By acidifying this filtrate with hydrochloric acid and boiling with tin the blue color is obtained.

PRODUCTION.

The production of tungsten ores during 1901 amounted to 179 tons, which were concentrated from 1,221 short tons of the crude ore. The concentrates varied from 60 to 70 per cent of tungstic oxide, and were valued at $27,720, which is an average of $154.86 per ton. The highest recorded price received for tungsten concentrates was $333 per ton, and the lowest $102. The general market price, however, was between $102 and $200 per ton, according to percentage of tungstic acid. The larger part of the tungsten produced in the United States was from Boulder County, Colo., with smaller amounts from San Juan County, Colo., from near Lead City, S. Dak., and from Long Hill, Conn. A considerable quantity of tungsten ore was mined at a number of other mines, but it was not concentrated nor sold-in some cases on account of its distance from the railroad, and in others on account of the prevailing low prices for the ore. At the Nevada mines, near Osceola, 1,200 tons of ore were taken out and are now lying on the dumps. At the rich mines in the Dragoon Mountains, Arizona, only the necessary assessment work was done. In the Arivaca district in Arizona, however, plans are forming for the erection of a mill for treating the tungsten ores that occur there. Of the crude ore, 2,918 short tons were recorded as having been mined in 1901.

As the amount of tungsten used in the arts is limited, there can readily be an overproduction, and the low price prevailing for the ore is partially due to its having been forced on the market in greater quantity than was demanded. The price increases with the percentage of tungstic oxide, and also according to its freedom from sulphur and phosphorus. The scheelite ore brings the higher price, as it is more easily treated than iron or manganese tungsten ores.

The price of tungsten ores has decreased from 50 to 75 per cent

during the last two years. An ore averaging from 45 to 55 per cent of tungstic acid will bring about $2 per unit, and ores running from 65 to 75 per cent will bring from $2.50 to $3 per unit, if they are free from phosphorus and sulphur.

MOLYBDENUM.

A few years ago there was but little demand for molybdenum minerals, except for their limited use in the manufacture of certain chemical reagents, but there is now a very noticeable increase in the market for these ores. The chief sources of this metal are the minerals molybdenite, MoS,, and, much less abundantly, wulfenite, PbMoO1.

Molybdenite is usually found in foliated masses or in scales, with a perfect basal cleavage and a metallic luster. When crystallized it is in short, tabular, hexagonal prisms. It is very soft, 1 to 1.5 in the scale of hardness, being readily scratched with the finger nail, and is of a pure lead-gray color. It is often mistaken for graphite (plumbago), which it sometimes very closely resembles; but it can be distinguished from graphite by its color, which is of a more bluish gray; by its streak on paper, which is gray to bluish gray-graphite is black-and by its behavior before the blowpipe, molybdenite giving off sulphur dioxide, which can readily be detected by its odor, graphite remaining unchanged when heated. Wulfenite is commonly found in square, tetragonal crystals, that are sometimes very thin; it is also found granulated and massive. It has a resinous to adamantine luster, and ordinarily an orange yellow to bright red color. It is usually found in veins with lead minerals.

OCCURRENCE.

Molybdenite generally occurs in beds, or is disseminated through crystalline rocks, principally granite, gneiss, syenite, and granular limestone; and it has been found sparingly in these rocks at many localities. It is found abundantly in the Western States, and a great amount of prospecting for it has been carried on. A number of new localities have been opened up during the last year, and some give. promise of containing this mineral in quantity.

California.-In Mono County a very promising molybdenite deposit has been developed 12 miles northwest of Bridgeport, on the west fork of the Walker River, by Mr. Robert A. Cameron and Mr. S. B. Fales, but it is now owned by Mr. Frank H. Saxton, of Carson City, Nev. As described by Mr. Saxton, there is a large ledge of white vitreous quartz, several hundred feet in width, which can be traced by a series of outcrops for a distance of nearly 3 miles. Where the development has been made there is an outcrop of this quartz 700 feet long by

300 feet wide. The molybdenite seems to be somewhat erratic in its occurrence, but it is always near the center of the wide vein of quartz, which is much more brittle where it contains the molybdenite than elsewhere. Sometimes the mineral is disseminated in particles through the quartz; at other times it is in concentric rings of small seams of molybdenite, and in seams of quartz up to 18 inches in thickness. This molybdenite-bearing core is about 20 feet in diameter. The molybdenite also occurs in pockets, containing as high as 20 pounds of molybdenite (MOS) and molybdite (MoO), the yellow oxide. Some pyrite was also found associated with the molybdenite. Although the work done has shown that there is a large quantity of molybdenite in the deposit, it has not demonstrated whether the molybdenite is concentrated sufficiently to make a profitable ore. It is also reported that on Alamo Mountain, in the northeastern part of Ventura County, a rich deposit of molybdenite has been found on property owned by Mr. Donald McDonald. The vein is said to be from 8 to 15 feet in width. In Los Angeles County a prospect is being developed by Mr. James B. Cook, of Los Angeles, Cal.

Washington.-Deposits of molybdenite are being worked by the Crown Point Mining Company, of Seattle, Wash., on Railroad Creek, in the Stehekin mining district, about 18 miles west of Lake Chelan, in the western part of Chelan County. The development work carried out by this company consists of about 110 feet of open cuts, and of two tunnels, one of which has been driven a distance of 195 feet westerly into the mountain, and the other has been driven 80 feet in a southwesterly direction. The molybdenite is associated with gold, silver, and copper ores, and, from what can be learned regarding its occurrence, it can be obtained in quantity.

Montana. At the Leslie copper mine, in the western part of Missoula County, Mont., considerable molybdenite was encountered in the upper parts of the mine. The property is being worked for gold. and copper principally, but, according to reports received from Mr. Wesly Everett, of Wallace, Idaho, president of the Leslie Copper Mining Company, considerable molybdenite was encountered in a 150foot drift which was run on a vein, and he states that they could obtain this mineral in quantity.

Utah.-Molybdenite has been discovered near Leamington, Millard County, by Messrs. W. G. Palmer and Brigham Clark, who have located claims covering these deposits. Not sufficient development work has yet been done to determine the exact extent of the deposits or of the percentage of molybdenum, but a sample of the ore sent shows it to be of good quality. The molybdenite occurs as small particles disseminated through quartz, and in places in small seams of almost pure molybdenite.

Arizona. In the Santa Rita Mountain district, Pima County, a vein of molybdenite 5 feet wide and carrying 15 per cent of this mineral is reported to have been found, but no definite information can be obtained regarding the correctness of this report.

New Mexico.-About 25 miles from East Las Vegas, San Miguel County, molybdenite occurs in considerable quantity. The property is owned mainly by Arthur N. Jordan, of East Las Vegas, but up to the present time nothing but assessment work has been done, on account of the uncertainty as to the actual value of the mineral. It is expected, however, that these deposits will be thoroughly developed during the coming year.

Molybdenite has also been reported to occur in quantity near Portage, Aitkin County, Minn., and near Cripple Creek, Colo., but thus far no definite information has been obtained regarding the exact location of these deposits, nor as to whether the mineral does occur in quantity.

Alaska.--In the vicinity of Skagway, Alaska, a molybdenite deposit has been developed to a limited extent by Mr. J. R. Rollins, of Skagway, who writes that the deposit consists of white quartz that contains "kidneys" of molybdenite scattered through it, varying from the size of a man's head down to that of a pea. Sufficient work has not been done to determine definitely the value of the claim, but the indications are good.

USES.

For a number of years the principal use of molybdenum has been in the manufacture of certain chemical reagents, especially of ammonium molybdate, which is used in the determination of phosphoric acid. It is also used in the preparation of "blue carmine" for the coloring of porcelain. During the last few years it has been discovered that molybdenum gives very beneficial properties to steel, and a ferro-alloy of this metal is now being made to be used in the preparation of a special steel. It is often supposed that molybdenum is used at times in the place of tungsten in the manufacture of hard steels; but each has certain valuable properties that it gives to steel, which the steel manufacturers are rapidly beginning to appreciate, and the evidence of this is in the increased demand for this metal during the last year by the manufacturers of ferro-molybdenum. Molybdenum is sold as the metal, and also as a nickel-molybdenum alloy.

TEST FOR MOLYBDENITE.

A good test for the sulphide of molybdenum is to heat a fragment of the mineral on the flat surface of a piece of charcoal for a considerable time in an oxidizing flame. There is then deposited a short

distance from the assay a coating of molybdic oxide, MoO,. This is pale yellow when hot and almost white when cool. This oxide is volatile in the oxidizing flame, but if touched for an instant with a moderately hot reducing flame it assumes a beautiful ultramarine-blue color.

PRODUCTION.

The production of molybdenite in the United States during the year. 1901 has probably not been over 10 to 15 tons. This does not begin to represent, however, the amount that is demanded by the market. The actual value of these molybdic ores is not easily determined, as the quotations vary widely from 10 to 15 cents up to $1.10 per pound. The ore, to be marketable, must contain over 45 per cent of molybdenum, and be free from copper. The average price of a 50 to 55 per cent ore is probably about $400 a ton.

Considering the demand for this mineral, there should be a large increase in the production of 1902 over that of 1901. As in the case of tungsten, the amount of molybdenum used is limited, and the market could readily be oversupplied, when at once the price would be very materially reduced.

URANIUM AND VANADIUM.

During the last few years there has been some demand for these metals for experimental work as to the beneficial properties which they impart to steel. Thus far, however, no practical results have been obtained, although it has been shown that both ferro-uranium and ferro-vanadium alloys, when added in small amounts to steel, do give beneficial results. Experiments are still being made along this line. This demand for these metals has stimulated prospecting for them, so that now the minerals containing them are found in considerable quantity, whereas formerly their occurrence was supposed to be rare.

OCCURRENCE.

The minerals that are the source of uranium and which are known at the present time are uraninite, gummite (an alteration product of uraninite), and carnotite. The last mineral contains also a considerable percentage of vanadium.

The principal occurrences of uraninite are at the Wood, the Black Hawk, and the Kirk mines near Central City, Gilpin County, and on Dolores River, at the mouth of Disappointment Creek, 80 miles west of Dolores, Montezuma County, Colo. It has also been found on the eastern slopes of Paradox Valley, in Montrose County, Colo. In South Dakota it has been found in the Ross Hannibal mine, in the Ruby basin of the Black Hills, but thus far it has not been definitely determined