The Diamond Joe Mine is in the White Picacho Mining District, in the extreme southern part of Yavapai County, Arizona. It is nine miles northeast of Wickenburg, which is in Maricopa County on the Santa Fe Railroad. The group consists of eight full claims, not patented. They belong to the Diamond Joe Mining Co. Inc. an Arizona corporation but the entire stock of this is owned by Mr. George R. Koyk, of Wickenburg. The claims are shown on a map marked A-5 accompanying this report. They are on record in the county seat and the company has available a full certified abstract of title. The claims were located about 1890, and minor work done intermittently until 1926-27, when Mr. Koyk and associates equipped the mine with machinery and developed extensively, built a fine mill and barely started operations when they were forced to shut down, not having enough water to operate steadily. The mine and mill have not been operated since.
The claims lie on a granitic igneous rock, which we may call grano-diorite. This isintruded extensively by dikes of various kinds, ranging from basic andesites to very acid rocks. There is considerable faulting and the vein or orebody is in the main fault, a north-south fissure dipping about 50 degrees west. None of the intrusive dikes cut across this and although we have at least two known faults crossing the vein they dislocate it hardly any and are therefore not of economic importance. All of the above disturbance is in the hanging wall, the footwall area being a relatively undisturbed area of diorite, solid and little altered. The highly intruded condition of the hanging wall has resulted in extensive kaolinization, with schistocity, and the general result is a badly broken, distorted, kaolinized area over the ore.
The ore outcrop is plainly seen and can be traced continuously, allowing for short stretches where it disappears under washes, for about 1200 feet, and, from sporadic indications of the same fissure, for a probable total length up to 3000 feet. The mineralization is principally a calcite gangue carrying lead and silver minerals, with considerable iron stain in places, and evidence of an intrusion of porphysy along the fissure.
Early work followed the vein down on an incline (shaft No. 1) which eventually connected at the 83' level with a later vertical shaft (No. 2). Later a new working shaft was sunk 500' and connected with Nos. 1 and 2 by drifts and raises. The deepest working level is 225', all elevations starting at the collar of shaft No.1. This 225'; vertical represents 325' on the incline of the vein. The relations of all the above are shown on attached general map marked B-C-3 and on cross section map F-2-6, the latter being from my own observations and surveys, and the former adapted from former surveys and amplified by me. At present the mine is full of water to the 157'; level. Shaft No. 3 is caved in near the surface. The other shafts are open and in good condition, and all drifts and raises are open as indicated on the maps and may be inspected down to water level.
Attached prints No. B-G-6- 7-a, and B-G-6-7-b show the arrangement of the plant buildings and attached also is a photograph showing the same. The buildings are all of timber frame covered with galvanized iron. They all have concrete floors and retaining walls, with rock or concrete foundations, and are all in perfect condition. There is an office and garage 16'; square, 2 stories, and a staff mess house 16 by 30' not shown on prints.
The main equipment on the ground is:
| Power house | Benz 240 H.P. full diesel engine with 175 K.V.A., 440-volt generator and 9 KW, 175-volt exciter, with switchboard, tools and fittings complete, and one power drill press with motor. |
| Shop | Complete blacksmith forge with blower and tools; pipe cutting equipment to take up to 8 inch pipe; one No. 5 Ingersoll Leyner drill sharpener; one small drill press. |
| Hoist house | One direct drive Diesel compressor--C. P. - 309 cu ft air per minute; one gas driven 40 H. P. Western Hoist; small motor driven priming compressor with air tank and gauge; two steel air receivers 3.5 by 9', and 3 by 5-1/2'; by. One wood gallows frame 27' high. |
| Assay Office | Complete equipment except muffle furnace includes, Braun crusher and pulverizer, motor driven; pulp balance, button ballance, and scales; full line of chemicals and glassware. |
| Tanks | 1000 gal. fuel oil tank. 4300 gal. cooling tank with slat cooler on top. 10000 gal, water storage tank-steel 50000 gal. water storage tank--wood stave |
| Mill | 9" by 16" Universal jaw crusher Automatic feeder to rod mill 4' by 8' Marcy rod mill 22' Doer classifier--drag type 3-K-K flotation machines 1 Whilfley table 1 Doak vacuum pump 1 6' by 4' Oliver filter 1 28' wood stave tank with Doer thickener for tails Sand and circulating pumps; motors; belting, shafting, and piping |
| Miscellaneous | Surveyors transit, rod, tapes; adding machine; typewriter; 5 mine cars. |
The buildings cost $13,000.00 and the equipment $65,000.00. The machinery has been well taken care of and is in perfect condition. The mill is rated at 100 tons daily capacity. By installing an intermediate Symonds cone or other crusher it could be readily enlarged to 130 or 140 tons. Attached is a print marked B-H-2-a showing flow sheet.
In estimating tonnage there is not enough systematic development to measure blocked out ore accurately. The outcrop to the north is continuous on the surface for 800' and the vein is developed continuously on the 225' level for over 600' with the limits not yet reached. The only continuous cross-section of the ore from top to bottom that can be studied is that shown on Map Exhibit F-2-b. This shows a minimum thickness of ore above the water level of over 9'. The ore on the bottom level, 68' under water is shown by their records, as 5' thick. I, therefore, find 8' as a conservative estimate of the ore width. Therefore, I feel that, as everywhere we have found the ore continuing on the bottom level, I should take the length of the surface outcrop as the length of developed ore or 800' in the north end (where all the mine workings are driven). The incline depth to the bottom level is 325', and I allow nothing below that. The width is 8' and the ore in place 13.5 cu. ft. to the ton. I thus arrive at 154,000 tons of developed ore. To the south is a similar outcrop of the same vein, easily traced for 400' and this had just been struck on the 225' or bottom level when the mine was closed in 1928. It was found but no development done. Open cuts on the surface show it stronger and wider even than the outcrop further north, with the same lead silver mineralization. I see nothing to indicate that this portion of the vein will not be at least as good as the developed portion and, using the same figures I arrive at a tonnage of 77,000 tons, called probable ore.
As the outcrop is identical throughout it's length, I mean in character and type, and as everywhere so-far developed the ore proves to go down, I think the above indicated tonnage is proven far beyond any doubt. Furthermore I find the same vein outcropping intermittently for over twice the length used in estimating (sand washes and dikes conceal most of its extensions).
We know that there are sure to be some horses of waste in this vein and also some ore destroyed where the faults cross, but we also know of two other veins which show lead and silver that should eventually produce ore, and we also have reason to expect development on the main vein beyond the 1200' in length used.
I, therefore, am not making any allowances and believe that for present purposes I can safely assume the tonnage shown as 231,000 tons.
As far down as can now be reached both the lead and silver minerals are mostly in oxidized forms. There is some galena but most of the lead is in cerrusite (carbonate) and anglesite (sulfate). On the 225' level the silver is said to begin to appear as a sulphide, but above one finds very little silver sulphide.
The vein has a banded structure and generally shows crystalline calcite towards the foot wall with from 2 to 4 feet of stained leached, calcareous material towards the hanging wall. Commonly, the parting banding between these formations carries heavy lead over a width of from an inch or two to over a foot in width, and also the values are commonly better near the hanging wall, but in general, one finds the lead or silver minerals anywhere across the vein. The bottom part of the present workings shows only patches of the crystalline calcite and the entire vein width for fifty feet above the present water level is a red, oxidized, porous matrix carrying considerable chert, See cross section F-2-b for 59' above water level.
There is not enough data available to make any accurate estimate of metal value for the total estimated tonnage, owing to the flooded condition of the two bottom levels and the absence of any but hearsay records. There can be no question that they found the vein on the bottom level and that it had good silver values and some lead. Also there is plenty of evidence that the lead values are much lower on the 180 and 225 (290) foot levels than above. I took three samples, 1-2 & 3 G., as shown on attached section F-2-b, that indicate this. They were taken here primarily to find how the values varied with vein width, as this location is the only available place in the mine with a good exposure all the way from foot to hanging wall. The values could not be taken as average however, for the other side of this 20' wide stope contains much more vicible mineral that the side sampled.
The samples ran:
| No. | Width of Sample | oz. Silver | % Lead |
|---|---|---|---|
| 1-G | 6' 7 in. | 13.58 | 1.4 |
| 2-G | 9' 6 in. | 9.04 | 0.4 |
| 3-G | 12' 0 in. | 6.96 | 1.5 |
| Average | 9' 4 in. | 9.25 | 1.1 |
However, we have a good sampling record above the 83' level - about 125' on the incline. This sampling was done by A. L. Beale, a competent engineer. I took samples 4-G, 5-G-F, and 5-G-R, shown on attached Section F-2-b, to check some of his samples and got a fair check. I have made a careful study of his sampling and assays underground. I estimate from his results and my own checking and estimating that the red oxidized material near the hanging wall runs 23.6 oz. silver and 7.25% lead over a width of 3 to 4 feet. The white calcite towards the footwall runs 7 oz. silver and 11.6% lead over a width of 5 to 6'. The weighted average ore therefore above the 83 foot level (125) is 12.5 oz. silver and 10.15 % lead. For purposes of estimating I will call this 12 oz. silver and 9% lead. There should be enough of this ore to run a 100 ton mill 2.5 years with profits as indicated later.
It would seem to me that the sensible plan of operation for this mine would be to start to mine the ore from the 83' level up, through No. 2 shaft. When the mill was in steady operation, No. 3 shaft would be repaired and hoisting would be transferred eventually to that shaft, but at leisure. One strong reason for doing this is the necessity of conserving the water now in the mine, which should carry the mill for several months. It will be necessary to get other water as explained later but before going into that and equipment expenses, I present here estimated costs and profits on the above basis.
I estimate the probable costs to operate as below:
| Cost per ton Concentrates | Cost per ton wet ore | ||
| Wet | Dry | ||
| Mining | $2.12 | ||
| Milling | $0.96 | ||
| Supervision | $0.47 | ||
| Haul to R.R. | $1.00 | $1.18 | $0.20 |
| R.R. Frt. | $7.60 | $8.94 | $1.49 |
| Smelter Treatment & deductions | $6.20 | $1.03 | |
| Silver deduction | $2.78 | $0.48 | |
| Lead deduction | $13.56 | $2.26 | |
| TOTAL | $9.01 | ||
The cost is based on 100 tons per day. Tests made in 1927 indicate that 6 tons of ore will make 1 dry ton of concentrates and that concentrates as shipped run 15% moisture. Mining and milling costs were arrives at by setting up in detail the labor cost to operate, and calling that 60% of the total for mining, and 40% of the total for milling, these percentages being based on the experience figures of similar operations. Allowance was made for two crews on development. The silver and lead deductions shown represent the difference between the gross value of these metals delivered to the smelter, and the amount they actually pay. These items theoretically cover metallurgical losses, and refining and marketing costs.
Deducting the cost per ton, $9.01 from the gross value per ton $12.32 (after 15% mill loss) leaves an operating profit of $3.31 per ton. From this taxes will eventually be deducted and these will probably amount to from 20% to 25%. Present metal prices are used - that is 64.5 cents silver; and 3.75 cents lead.
There are no apparent complications about this operation and I am quite sure that the above estimates can easily be attained, and profits exceeded, in practice. The mining of the ore will have to be carefully planned and intelligently supervised owing to the bad hanging wall but I see no reason why a system cannot be developed that will take care of this cheaply. Mill tests have been made on the ore and beyond a doubt recoveries of 85 to 90% of the values can be recovered. The principal obstacle now is the water supply. The mine itself when it was being operated made an average of 15 gals. per minute which is about half the requirements. It will be necessary to install a 4 inch pipe line about 3 miles long to insure water. A well at that distance is available and probably adequate, according to Mr. Koyk.
Before operations can start certain preparations must be made. The mill requires minor remodeling and equipment. The main or No. 3 shaft is caved near the surface and probably will have to be reblocked and repaired to the 290 (225)' level. Shaft No. 2 is open, but is only one compartment, cribbed, down to the 83' level. From there to the bottom at the 180' level it is regularly timbered, one and one half compartments.
I estimate initial expense to start operations on the above schedule to be:
| Repairing No. 2 shaft and enlarging to surface (one and one half compartments) | $2,500.00 |
| Equipment at No, 2 shaft: | |
| 35 H. P. gas Hoist; 2 cooling tanks; air and water pipes; head frame and bin; cage; aerial tram to mill; installing; | $6,500.00 |
| Drifting, and preparing stopes | $5,000.00 |
| Mill remodeling: | |
| 1 Whilfley table; 1 concentrate thickener; 6 flotation machines; 1 concentrate dryer; installing; | $7,135.00 |
| New change room, with office room; | $1,500.00 |
| One light truck | $1,000.00 |
| Supplies at mine: | |
| 2 cars timber; fuel oil; 4 stoper drills; 4 jackhammer drills; bars and mountings; steel; air water hose; rails; 6 mine cars; powder; fuse; caps; carbide; oil; small tools | $7,500.00 |
| Supplies at Mill: | |
| 1 car flotation, reagents and chemicals | $3,300.00 |
| Accident Insurance payment | $2,500.00 |
| Water development, Pump, and 3 miles 4 inch line | $1,500.00 |
| TOTAL | $52,825.00 |
Nothing has been allowed above for repairing the main shaft No. 3. It is impossible to estimate this and if it is desired to put in a figure in the initial estimate it cannot be based on information. As we know that it is caved in several places and that probably the 290 foot level (225) is also caved, I do not think it safe to allow less that $10,000.00 additional for this work. I do not think there is the least doubt but that the ore is there and that the above program and operations can be carried out within the estimatesgiven. Preparing the mine for stoping 100 tons of ore per day will be the job requiring most time and I think at least three months will be required before the mill can start. The mill eventually will be fed through the main or No. 3 shaft and the ores now under water treated. There can be little question that these ores will be profitable and greatly extend the life of the mine, but they will, under the above program come into the picture normally and naturally without being essential to steady operation for a year or two. It seems likely that an enlargement of the power plant will some day be advisable, so that the mine as well as the mill can be operated electrically, but these changes will come along after operations are proceeding profitably. In figuring values in this report nothing has been allowed for gold. The ore averages something better than 0.01 oz. per ton which is below the limit customarily paid for at custom smelters, and nothing was, in the past, received for it. However the amount of gold would be of importance over a term of months and doubtless the smelter contract when based on steady regular shipments, would be drawn to provide for gold payments.
In Mr. Sedgwick's report, attached, the mine is described as of a period when development had reached only to the 83' level. His figures, therefore, cover the same ore extent that I have used. He finds the average value of the ore to be 14.89 oz, silver and 8.4% lead. It wil1 be noted that the claim lines as shown of the claim map, attached, Exhibit No. A-5. are not consistent, with those shown on the general map, Exhibit No. B-C-3. I find that Mr. Koyk's locations and monuments actually cover the entire vein outcrops continuously, but the aids and end lines have not been accurately surveyed. The ground is fully covered and protected, but when a survey for patent is made it will be found necessary to establish the exact end and side lines accurately by amending the present locations. Exhibit No. A-5 is therefore an idealized picture of what the eight claims actually and in fact cover.
With this mine equipped and developed as it is, there is no possibility of its failure to make substantial profits under even the conditions now existing. Present opinion seems to be general that silver will soon be forced to the legal limit of $1.29 per ounce. I estimate that this would increase the profit from $3.31 to $9.20 per ton. Wage increases and cost of supplies would presumably be higher under this condition, but in any event, and with full realization of the uncertainty of economic forecasts at this time, it seems to me extremely probable that profits from the Diamond Joe mine will, in the near future, considerably exceed the $3.31 per ton basis I have used.
August 1934 Signed W. B. GOHRING
Mining Engineer, Phoenix, Arizona
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