Hardy Mine (Miller Mine), Oatman Mining District, Black Mountains, Mohave County, Arizona, USAi

Regional Level Types
Hardy Mine (Miller Mine)	Mine
Oatman Mining District	Mining District
Black Mountains	Mountain Range
Mohave County	County
Arizona	State
USA	Country

MILLER MINE.

Location and history. The Miller (formerly the Parsons and the Hardy) mine is 2 miles southwest of Gold Road, on the south side of Silver Creek, mostly in a hill on the northeast slope of Hardy Mountains, an outlying group of the range, at about 2,200 to 2,400 feet elevation. The mine was discovered early in the sixties. It was worked by adit drifts, and some of its ore was shipped to San Francisco, some was treated in arrastre, and some in the old Moss mill on Silver Creek. W. H. Hardy, of Kingman, a former owner, states that he took out $80,000 worth of ore after a considerable amount had been mined and shipped by earlier owners. Later Frank Holmes became interested in the mine and soon began shipping ore; still later the mine was taken over by Col. Thomas Ewing, of Vivian, who sunk a 200-foot shaft on it, and drifted and crosscut the vein with good results. The property is now owned by George Miller, of Gold Road, who has been connected with it since about 1892. It
comprises six claims. The production to date is reported to be $100,000, of which $80,000 was stoped from a comparatively small space.


Developments. The mine is developed to a depth of about 300 feet, principally by three shafts aggregating 500 feet, three tunnels and a drift amounting to nearly 1,000 feet, and about 200 feet of crosscuts. The principal surface equipment is a gasoline hoist. Good potable water, said to be plentiful for domestic and milling purposes, is derived from a well near the mine.


Geology. The country rock is the granite porphyry and micropegmatite described on page 30. It is a medium to coarse grained rock and weathers pale purplish and brown; it contains many finegrained magmatic inclusions or "schlieren," and, as at the Rattan mine, above described, it is, locally at least, pyritic, though no pyrite has yet appeared in the veins. It is sheeted about vertically northsouth and east-west. It is intruded and in part overlain on the north by micropegmatite, which is to some extent altered and mineral bearing, and it is seemingly intruded by rhyolite on the east. It is also intruded by dikes of a dark greenish altered rock, probably a diabase.

Vein and ore. The Hardy vein is reported to have a length of 4 miles. It strikes about N. 80° W. and dips about 75° N. Toward the west the Jack Pot, Homestake, and Navy Group mines and other openings are situated on it. (See PL X.)

The Miller mine is located on the east end of the Hardy vein, which here has an average width of about 15 feet and a maximum width of about 30 feet, as shown by cuts and croppings at the east shaft. The croppings consist of quartz and silicified rock-stained by iron and manganese. The vein is composed principally of quartz, a small amount of calcite, and some altered rock, which seems to be the younger micropegmatite. Much of the quartz, as shown in the deep workings and in the croppings, has replaced calcite, after which it is pseudomorphic. Plate II, reproduced from a photograph of a specimen collected in the main drift about 600 feet from the mouth and 200 feet below the surface, represents this ore. Some of the quartz is drusy, many of the vugs containing slender brittle quartz needles. The vein contains also. considerable greenish crystalline fluorspar, which faces slabs of quartz a foot or more in diameter with incrustations one-half inch thick. Adularia is also present in the vein, along with the quartz of variable grain which replaces calcite. The occurrence of what seems to be altered micropegmatite in association with the vein suggests that the fissure now occupied by the vein may formerly have been occupied by a dike of the micropegmatite, which the vein later replaced.

Beside the main vein above described there are also several smaller veins. In the middle east slope of the hill in which the mine is located the vein near its east end is intersected by a smaller northsouth vein. This cross vein varies from 6 inches to about 3 feet in width and is younger than the main vein, which it cuts. It is otherwise similar to -the main vein and has received considerable development in the mine, mostly to the north of the main vein, and has contributed materially to the production.

The ore of the Miller mine contains chiefly gold, but carries also considerable silver more silver, it is said, than any other ore in the district or southern part of the Black Mountains. The ore is reported to average about $6 a ton, but some very rich ore is also present.