The Ray Mine is located in eastern Pinal County, Arizona, about 80 miles southeast of the city of Phoenix. Ray consists of a large classical porphyry copper deposit.

The Ray sulfide system is developed in a variety of Precambrian rocks and Laramide intrusives. The bulk of the hypogene sulfides pyrite, chalcopyrite and molybdenite— occur in schist, the Ruin Granite (a quartz monzonite), quartzite and diabase, all Precambrian in age. Diabase is the youngest Precambrian rock and occurs as dikes and sills in all the older “country” rocks; it is the most receptive rock to copper mineralization and hosts the bulk of the ore at Ray. A series of Laramide (late Cretaceous) intermediate to acidic composition dikes and stocks, representing at least 12 different rock types, intruded all the older rocks. All Laramide rock types have been affected by the later Ray hypogene sulfide system and are cut by sulfide veinlets. Post-mineral Oligocene, Miocene and later volcanic and clastic rocks unconformably overlie part of the sulfide body. Major high-angle, northwest-trending normal faults extend through the deposit area, intersected by major northeast trending faults at the north end of the deposit with major deformation occurring before, after and perhaps during intrusion of ore-age dikes and stocks.

Hypogene mineral zoning is concentric, with a central low-grade core characterized by low total sulfides and a high cpy/py ratio. A higher grade zone (the “ore zone”) surrounds the low-grade core and is characterized by higher total sulfides but with a lower cpy/py ratio than the core. The increase in total sulfides continues regularly outward from the low-grade core but with a decreasing cpy/py ratio resulting in an outer high-sulfide, low copper, pyrite halo. Importantly, the center of this zonal pattern does not coincide with that of any of the porphyry stocks. Neither the deposit nor the intense depositassociated alteration coincides with the densest dike swarms and largest plutons of ore age exposed near the economic mineralization. Based on K-Ar dating from hydrothermal and igneous biotites, the alteration halos were developed at the same time as the Granite Mountain Porphyry which outcrops 4 miles S70°W from the orebody. Systematic changes of sulfide content and copper grade are related to rock type changes (quartzose Precambrian rocks, diabase, and Laramide porphyry) in the Ray orebody.

The Ray mine is an open pit mine.

The current footprint of the Ray open pit is elliptical in shape and measures 4.3 kilometers from east to west and 2.7 kilometers from north to south, with the elevation of the highest bench being 915 meters and the lowest bench being 260 meters above sea level.

The Ray Operations consists the Ray Mine and SX-EW Plant, the Ray and Hayden Concentrators, the Hayden Smelter and the Copper Basin Railroad.

Currently, sulfide ores from the Ray Mine are processed at two facilities, the onsite Ray Mine Concentrator and the offsite Hayden Concentrator located approximately 20 miles away.

A local railroad, Copper Basin Railway, transports ore from the mine to the Hayden concentrator, concentrate from the Ray concentrator to the smelter, and sulphuric acid from the smelter to the leaching facilities.