434  OKLAHOMA—1992materials that have long been a problem, thereby
eliminating the need to mine other resources to satisfy fuel requirements.

 
Clay and Shale.—In 1992, Oklahoma 
ranked 18th nationally among 44 StateS reporting clay and shale production.

Nine companies, operating 13 mines in 8 
counties, reported production of common clay and shale. Production of 621,944
metric tons, valued at $3.3 million, was 
202,232 metric tons and $882,000 less 
than amounts estimated for 1991. Production reported from companies in Pontotoc,
Rogers, and Seminole Counties accounted for approximately 92% of the total.
Clay and shale are abundant 
throughout the State and are used mainly 
in the manufacture of portland cement (almost 48 %), common brick (44%),
concrete block (almost 6 %), and structural concrete (about 1 %). Highway
resurfacing, stoneware, and pottery manufacture accounted for a smaller portion
of the clay used. The major production was near Oklahoma City and Tulsa.

 Four companies manufactured brick at five plants in the State in 1992. Face,
common building, and paving brick, as well as crushed brick for landscaping,
were produced by Acme Brick Co., at plants in Edmund, Oklahoma County, and~
Tulsa, Tulsa County, and by Mangum' Inc. Brick Co. from a plant at Mangum,
Greer County. Commercial Brick Corp. 
~ produced face and common buildingbnck 
'  from a plant at Wewoka, Seminole 
'  County. And Oklahoma Brick produced 
~ face, common building, and paving brick from plants at Muskogee, Muskogee
County, and Union City, Canadian County. 
 
Feldspar.—Oklahoma ranked third of 
seven States producing feldspar in 1992. 
Reported production and value each decreased about 1 % below 1991 totals.
Arkhola Sand and Gravel Inc., a division of APAC Arkansas Inc. , produced
a feldspar-silica concentrate that was sold to the glass and ceramics industries.
Alumina contained in the feldspar imparts 
corrosion resistance to the final products. Feldspathic sand was dredged
from the Arkansas River near Muskogee, in 
Muskogee County. The sand was dried, iron impurities were removed by 
magnetic separation, and the sand was 
leached with acid to remove other 
impurities, redried, and bagged for 
shipment. 
 
Gypsum.—Oklahoma ranked 1st 
among 19 States reporting crude gypsum production and 7th among 28 States
reporting productiOn of calcined gypsum in 1992. Crude gypsum production
of more than 2.6 million short tons increased almost 10.5 % over that reported
by producers in 1991. Value was more than $14.9 miffion, almost 15.4% above
the 1991 value. Seven 
companies reported crude gypsum 
production from mines in Blaine, Caddo, Comanche, Jackson, Kingfisher, and

Woodward Counties. Calcined gypsum production was reported by three of the
same companies in Blaine, Comanche, and Jackson Counties. Harrison Gypsum
Co. Inc. , Temple-Inland Forest Products Corp., and United States Gypsum
Co. were the three largest producers of crude gypsum in the State. Harrison
Gypsum Co. Inc.'s Cement Mine, in Caddo County, and Temple-Inland Forest
Products Corp.'s Fletcher Mine, in Comanche County, were the fourth and eighth
largest producers, respectively, in the United States. 
 Gypsum was mined in western Oklahoma, from the Nescatunga and Shimer Gypsum
Members of the Permian Blaine Formation and from the Permian Cloud ChiefFormation.
The mineral was used as plaster for interior walls and wallboard, retarder
in cement manufacture, fillers, soil conditioners, and a variety of medical
and other uses. 
 The gypsum market continued to be pressured by overcapacity and record-low
prices. Substantial increases in available gypsum from flue gas desulfurization
could create major concerns for the industry. The industry continued to rebound
in 1992, primarily from the increase in residential construction. Commercial
construction was somewhat 
limited to repair and remodeling. The 
upward trend was expected to continue 
into 1993. 
 
Iodine.—Oklahoma was the only State 
reporting iodine production in 1992. Production in 1992, nearly 2 million

kilograms, was almost 4,000 kilograms 
less than that of 1991. Value in 1992 was almost $20.9 million, about 33
% less than the 1991 value of nearly $31.4 
million. Three companies, loChem Corp. , North American Brine Resources,
and Woodward Iodine Corp. , in the 
northwestern part of the State, produced crude iodine from oilfield brines.
The brines were obtained from the 
Pennsylvanian Morrow Group in Dewey, Kingfisher, and Woodward Counties and
supplied about 62% of domestic demand for Iodine. 
Major uses of iodine included animal 
feed supplements, catalysts, inks and dyes, pharmaceuticals, photographic
equipment and recycling processes, 
'  sanitary and industrial disinfectants, 
~ stabilizers, and radiopaque media~ Other 
'  uses included batteries, high-purity 
~ metals, motor fuels, iodized salt, lubricants, and cosmetics. 
 
 Lirne.—In 1992, Oklahoma ranked 24th among 32 States reporting
lime
production, all from the St. Clair Lime Co. plant in Marble City, Sequoyah
County. Limestone was mined underground by room-and-pillar methods from the
Silurian St. Clair Limestone and converted to crushed limestone, quicklime,
and hydrated lime. Total lime production and value decreased 1 .6 % and 0.3
% , respectively, in 1992. 
 Growth in the lime and limestone industry was expected to increase as a
result of the Clean Air Act Amendments of 1990 and other environmental legislation
that required installation of stack scrubbers at coal-fired powerplants.
Scrubbers utilize lime and pulverized limestone to remove sulfur oxides from
stack gases~ Other areas of continued growth in usage included water treatment,
to achieve proper pH balances, and treatment ofsewage sludge and hazardous