Red Devil Mine

Mine, Inactive

Commodities and mineralogy

Main commodities Hg; Sb
Other commodities Au
Ore minerals cinnabar; stibnite
Gangue minerals carbonate; quartz; sericite

Geographic location

Quadrangle map, 1:250,000-scale SM
Quadrangle map, 1:63,360-scale D-4
Latitude 61.75947
Longitude -157.31375
Nearby scientific data Find additional scientific data near this location
Location and accuracy The main shaft of the well-known Red Devil Mine is about 0.3 mile from the mouth of Red Devil Creek; the location of the mine is labeled on the 1:63,360-scale USGS topographic map. The mine is in the SE1/4 sec. 6, T. 19 N., R. 44 W., of the Seward Meridian. The Red Devil Mine is locality 22 of Miller and others (1989).

Geologic setting

Geologic description

The Red Devil Mine is the largest mercury mine in Alaska and the most important lode mine in the Sleetmute quadrangle. The deposit has been described in detail by Webber and others (1947), Cady and others (1955), Herreid (1960, 1962), Malone (1962), MacKevett and Berg (1963), Sainsbury and MacKevett (1960, 1965), and Miller and others (1989). The following description summarizes those reports.
The rocks in the vicinity of the Red Devil Mine area consists of sandstone, siltstone, and shale of the Upper Cretaceous, Kuskokwim Group that have been cut by high angle, altered mafic dikes. The mineralized area is on the southern flank of the Sleetmute anticline, which strikes approximately N45W and plunges 5 to 10NW. The sedimentary rocks dip 45 to 60 degrees on either side of the anticline. Mafic dikes crosscut the sedimentary rocks at angles of 45 to 60 degrees.
Mineralization consists of cinnabar and abundant stibnite; realgar and orpiment are minor constituents. The cinnabar and stibnite form massive aggregates, encrustations, breccia fillings, and vug linings. In places both minerals are exceptionally well formed; cinnabar crystals from the Red Devil Mine have been displayed in mineralogical museums throughout the United States and Europe. Ore shoots formed at or near the intersections of altered dikes and numerous northwest trending faults that generally parallel the bedding in the Kuskokwim Group rocks (Sainsbury and MacKevett, 1960, 1965; MacKevett and Berg, 1963). Typically, the cinnabar-rich ore bodies that formed at the fault-dike intersections are pencil-shaped and plunge about 40 degrees south. The ore bodies that were mined range from 4 inches to 4 feet thick and continue along plunge for up to about 400 feet. The richest ore occurred in a zone at least 600 feet wide and 1,500 feet long.
Herreid (1960, 1962) and Malone (1962) described vertical mineral zonation in the Red Devil ore bodies. Near-surface ore bodies are generally composed of quartz and cinnabar, and the stibnite-cinnabar ratio increase with depth. On the fifth and deepest level, about 600 feet below the surface, ore shoots consist mainly of stibnite-quartz and contain only minor amounts of cinnabar (Bundtzen and Miller, 1997). Although Jasper (1961) stated that no native mercury was identified on the property up to 1960, prospectors have panned native mercury on McCally Creek west of the property. MacKevett and Berg (1963) report that clay minerals (dickite) occupy central parts of the ore-bearing veinlets but are most conspicuous in barren veinlets distant from ore bodies.
Fluid inclusion studies by Roedder (1963, 1972) and Belkin (1993) support the interpretation that ore deposition took place at relatively shallow depths in the hydrothermal system. Homogenization temperatures of Red Devil cinnabar crystals range from 158 to 164 degrees C and quartz vein materials homogenize between 169 and 210 degrees C; salinities range from 1 to 4 percent NaCl (Belkin, 1993). Gas fluids from Red Devil are CO2 enriched and are depleted in N2 and CH4; the two-phase liquid-vapor inclusions are typical of those observed in epithermal deposits (Gray, Gent, and others, 1997). Assuming densities and trapping temperatures of 160 to 200 degrees C, the deposit formed at pressures of 1,500 bars or less, probably within a hot springs plumbing system.
Mining has taken place intermittently. From 1933 to 1946, 2,972 flasks of mercury were produced from high grade, shallow ore bodies (Webber and others, 1947). An estimated 29,369 flasks were produced from 1953 to 1963 and 3,800 flasks were produced from 1969 to 1971 (Bundtzen and Conwell, 1982). A total of about 36,141 flasks of mercury were recovered from 74,000 ton of ore with an average grade of about 1.50 percent mercury. In 1970-71, stibnite was recovered using a flotation process and marketed as a sulfide concentrate.
Geologic map unit (-157.316125314082, 61.7587801457821)
Mineral deposit model Silica-carbonate mercury (Cox and Singer, 1986; model 27c).
Mineral deposit model number 27c
Age of mineralization Undated; the nearby Fairview prospect (ARDF SM019) has a 40Ar/39Ar age of 72.6 Ma (Gray, Gent, and others, 1997).
Alteration of deposit The mafic dikes in the ore zones are largely converted to silica-carbonate rocks; the clay-mineral dickite is ubiquitous in the altered dikes.

Production and reserves

Workings or exploration
The Red Devil deposit was discovered by an unidentified berry picker and later staked by Hans Halverson in 1933. From 1933 to 1946, activity consisted mainly of surface prospecting and selective mining from both surface and shallow underground workings. In 1952, DeCourcy Mountain Mining Company acquired a lease on the property and obtained a Defense Minerals Exploration Administration (DMEA) loan. The mine achieved its peak productivity from 1953 to 1963 when the deposit was mined from five working levels off the 'Main' and 'Dolly' shafts, which are about 1,000 feet apart.
The underground workings total about 4,000 feet and extended to a depth of about 450 feet through 1964. There are also at least 3,300 feet of trenching. Hawley and others (1969) evaluated the mine for precious metals and detected elevated gold values.
Indication of production Yes; medium
Reserve estimates Unknown; abundant stibnite on the lowest (fifth) level was not mined.
Production notes
Mining has taken place intermittently. From 1933 to 1946, 2,972 flasks were produced from high grade shallow ore bodies (Webber and others, 1947). An estimated 29,369 flasks were produced from 1953 to 1963 and 3,800 flasks were produced from 1969 to 1971 (T.K. Bundtzen, written communication, 1988; Bundtzen and Conwell, 1982).
Mercury production started in the 1930s by processing float collected in Red Devil Creek and residually weathered material from the slopes to the side of the creek. The mercury was recovered using a Johnson McKay retort. Production was 158 flasks in 1940, 135 flasks in 1941, and 117 flasks in 1942. In late 1942, the New Idria Mining Company from California acquired the Red Devil Mine, constructed a retort and drove about 500 feet of underground workings. In 1944, 1,090 flasks were produced from 2,652 tons of ore (Jasper, 1961). In 1945, the company produced 962 flasks from 1,514 tons of ore. In 1946, R.F.Lyman leased the mine from the New Idria Mining Company and produced 500 flasks of mercury from an undisclosed amount of ore (Jasper, 1961).
Alaska Mines and Minerals, Inc. operated the mine from 1954 to 1963, when more than 80 percent of the production took place. During 1953 to 1954, about 1,084 flasks were produced from 2,500 tons of ore. From 1955 to 1960, approximately 19,800 flasks were recovered from 47,250 tons of ore (Jasper, 1961). Production in 1961 was 4,089 flasks and production in 1962 was 3,700 flasks, but production in 1963 and 1964 combined was only about 695 flasks (Jasper, 1961; Bundtzen and Conwell, 1982).
In 1969 to 1971 Alaska Mines and Minerals Inc. produced cinnabar and stibnite concentrates for shipment to Japan from both open pit and underground workings, and retorted some mercury on the property. The mill operated for most of 1970, but the mine closed in June 1971, due to a sharp drop in the price of both mercury and antimony (Fackler, 1972). There has been no further production. Over the life of the mine, a total of 36,141 flasks of mercury has been produced from about 75,000 metric tons of ore at an average grade of about 1.5 percent mercury (Bundtzen and Conwell, 1982).

Additional comments

Cinnabar crystals from the Red Devil Mine have been displayed in mineralogical museums throughout the United States and Europe.


MRDS Number A010655; A013443


Belkin, H.E., 1993, Fluid inclusion systematics of epithermal mercury-antimony mineralization, southwestern Alaska, USA [abs]: European Current Research on Fluid Inclusions Biennial Symposium, 12th, Warsaw and Cracow, Poland, June 13-18, 1993, Abstracts, p. 25-26.
Bundtzen, T.K., and Miller, M.L., 1997, Precious metals associated with Late Cretaceous-early Tertiary igneous rocks of southwestern Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 242-286.
Gray, J.E., Gent, C.A., Snee, L.W., and Wilson, F.H., 1997, Epithermal mercury-antimony and gold-bearing vein lodes of southwest Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 287-305.
Herreid, Gordon, 1960, Geology of the Red Devil quicksilver mine, Alaska [abs]: Geological Society of America Abstracts with Programs, vol. 71, p. 2086.
Herreid, Gordon, 1962, Structural geology of the Red Devil Mine: Alaska Chapter, American Institute of Mining, Metallurgical and Petroleum Engineers (AIME) Annual Meeting, University of Alaska, Fairbanks, 22 p.
Wells, J.T., and Ghiorso, M.S., 1988, Rock alteration, mercury transport, and metal deposition at Sulphur Bank, California: Economic Geology, vol. 83, p. 606-618.
White, D. E., and Robinson, C. E., 1962, Sulphur Bank, California, a major hot spring quicksilver deposit, in Engel, A.E.J., James, H.L., and Leonard, B.F., eds., Petrologic studies: A volume in honor of A.F. Buddington: Boulder, Colorado, Geological Society of America p. 397-428.
Reporters T.K. Bundtzen (Pacific Rim Geological Consulting, Inc.) and M.L. Miller (U.S. Geological Survey)
Last report date 4/30/2003