Southwestern Arkansas Mercury Mining District
by Art Smith
Member of the Houston Gem & Mineral Society


he Southwestern Arkansas mercury mining district is a one mile wide east-west band on the Athens Plateau, the southernmost portion of the Ouachita Mountains. This narrow band extends from western Clark County through Pike County into eastern Howard County. Further west in Sevier County, but not contiguous with the mercury district is the Arkansas antimony mining district which has a separate mineralogy and mining history. However, stibnite is common in the western end of the mercury district and absent on the eastern end. All of the mercury mineralization is in the folded and faulted east-west trending anticlines and synclines of the Paleozoic age Stanley Shale which is composed of about 25% sandstone and the Jackfork Sandstone. Although the shales may contain some mineralization, all the ore occurs in sandstone as disseminations and fracture and vein fillings. Some of the sandstone is so indurated that it appears more like a quartzite, and indeed, it is often called a quartzite.

Map of area

The first documented discovery of cinnabar in the district was in 1930. Following an announcement of the discovery by the state geologist in 1931, the size of the district and mining in it developed rapidly. Between 1931 and 1937 the district produced 4736 flasks of mercury from numerous mines and prospects. Then production and mining lagged for two years but increased dramatically with the marked price increase of mercury during 1940. The price of mercury was high, and so mining flourished through 1943 but then dramatically decreased with lower prices and depletion of known reserves. By 1947 the district was dead, and the only subsequent recorded production was 11 flasks in 1965 (Clardy & Bush 1976). Total production for the district was about 12,500 flasks with most of it coming from less than 10 mines, but over 50 mining companies had operated in the district during its 15-year period of activity. Discoveries were made strictly from surface outcrops which were followed into the subsurface. Very little core drilling was done to prove new reserves or to find new deposits, and most if not all was done by the U.S. Bureau of Mines during the war years and does not seem to have been very successful

The most notable deposits are those on Bemis Hill, Parker Hill, Parnell Hill, and the Bell, Caddo, U.S., Humphrey, and Gap Ridge mines. Perhaps the most interesting name was Parnell Hill’s Bloody Cut, no doubt named for the abundant cinnabar showing on the walls of the cut during mining. Although all of the cinnabar has been removed, the Bloody Cut and other pits and cuts can be observed along the wooded shores of Lake Greeson in the Cowhide Cove Recreation area. The mining activity occurred before dam building and lake formation, as was the establishment of the recreational area. With some diligent searching of the associated dump piles along the lake shore and in the woods, good traces of cinnabar still can be recovered.

Table 1 is a list of minerals reported from the district. Most of these occur only as microminerals. Larger specimens are uncommon but are available occasionally from older collections, particularly bright red sandstone with richly disseminated cinnabar. The cinnabar in sandstone helps distinguish it from Terlingua, Texas cinnabar specimens which are in a limestone and are much more numerous. Solid crystalline cinnabar may occur as vein and fracture fillings, and small crystals may occur in cavities. Some Arkansas locations have a red ocherous goethite-hematite mixture that masks much of the cinnabar or that can give an impression that there is more cinnabar present than there really is. Bright colorless transparent quartz crystals are not uncommon. They may be completely or partially doubly terminated and are more like Herkimer quartz crystals than most Arkansas quartz from the central Ouachita Mountains. They may reach 4 cm across, but most are smaller, and they are particularly attractive and desirable with red cinnabar crystals or inclusions or with cinnabar or stibnite. Most of the cinnabar crystals are bright to dark red and under 4 mm. They are not as well formed as the Chinese cinnabars and can be seen as equant, slightly rounded, single and twinned crystals, rods, some with branches, or fibers. Most of the other crystallized minerals occur only as micro crystals, but larger specimens containing them are rarely available. Calomel fluoresces a deep red under short-wave radiation and is present as smears and coatings. However, it is usually difficult to discern without a microscope even on larger specimens except with an ultraviolet light.

Clardy, B. F. and W. V. Bush 1976 Mercury District of Southwest Arkansas. Arkansas Geological Commission Information Circular 23.

McIlwaine, R. B. 1944 Southwestern Arkansas Mercury District, Howard, Pike, and  Clark Counties, Arkansas. U.S. Bureau of Mines War Minerals Report, unpublished, 41p.

Reed, J. C. and F. G. Wells 1938 Geology and Ore deposits of the Southwestern Arkansas Quicksilver District. U.S. Geological Survey Bulletin 886-C.

Roberts, A. C., M. A. Cooper, F. C. Hawthorne, R.A. Gault, J. D. Grice, and A. J.
Nikischer 2003 Artsmithsite, a new Hg1+-Al phosphate-Hydroxide from the Funderburk prospect, Pike County, Arkansas. Canadian Mineralogist 41:721-725.

Sohlberg, R.G. 1933 Cinnabar and associated minerals from Pike County, Arkansas

American Mineralogist 18:1-8.

Stearn, N. H. 1936 The cinnabar deposits in southwestern Arkansas. Economic Geology 31:1-28.

Table 1:

Minerals of the Southwestern Arkansas Mercury Mining District





anglesite (?)


white coating on galena

Clardy & Bush 1976



white, fibrous, xls micro, late.

Roberts et al. 2003



white to colorless, coarsely xline

Reed & Wells 1938



spheres, yellow fibers

EDS analysis



white to clear, uncommon

Clardy & Bush 1976



white to yellowish coatings

Sohlberg 1933



bright to dark red crystals

Sohlberg 1933



white powdery coatings

Clardy & Bush 1976



orange, crystalline

EDS analysis



yellow crusts turn black

Clardy & Bush 1976



white, 2-3mm discoidal xls

EDS analysis




reported McIlwaine 1944



red, yellow, brown, earthy & botr.

Reed & Wells 1938



mixed with goethite

Reed & Wells 1938



dark gray globular masses

Clardy & Bush 1976



liquid silver spheres

Clardy & Bush 1976



dark red to black coatings, xls

Clardy & Bush 1976



hyalite, clear to white coatings

Clardy & Bush 1976


Ca3Al7(SiO4)3 (PO4)4 (OH)3.16.5H2O

tiny white spheres

EDS analysis



smears, small masses, cubes

Clardy & Bush 1976



Clear, colorless to sli. smoky xls

Reed & Wells 1938



brown translucent xls in deeper mines

Reed & Wells 1938



gray acicular crystals, inclusions

Stearn 1936



pale yellowish stibnite pseudomorphs

Sohlberg 1933



yellow, crystalline,turns green-gray

EDS analysis