310 



UNITED STATES MINERAL RESOURCES 



schist near Spruce Pine, N.C. (Brobst, 1962), 

 Clarkesville, Ga., and other areas in the Blue Ridge ; 

 andalusite in the contact zones of gabbroic and gra- 

 nitic plutons in central Maine (Espenshade and 

 Boudette, 1967) ; and sillimanite schist in Hart 

 County, Ga. (Teague, 1950). 



The AlaSiOs minerals are also widely distributed 

 in micaceous schist and gneiss in Idaho, Montana, 

 Colorado, the Black Hills, S. Dak., the Sierra Nevada, 

 Calif., and parts of Washington (Thorsen, 1966) and 

 Oregon. However, the only deposits that are large 

 enough and rich enough to be regarded as im- 

 portant resources are the kyanite-sillimanite deposit 

 at Woodrat Mountain and the kyanite-andalusite 

 deposit at Goat Mountain, Idaho (Hietanen, 1956; 

 Van Noy and others, 1970) . 



QUARTZOSE DEPOSITS 



The principal quartzose deposits of kyanite-group 

 minerals are in the southern Piedmont (Hurst, 1959 ; 

 Espenshade and Potter, 1960). Nearly all domestic 

 kyanite production since 1950 has come from mines 

 at Willis Mountain and Baker Mountain, Va., at 

 Henry Knob in the Kings Mountain district, N.C. 

 and S.C, and at Graves Mountain, Ga. Most re- 

 sources of quartzose deposits are at these localities 

 and in other kyanite-quartz deposits in the Pied- 

 mont. Smaller deposits containing other minerals of 

 the kyanite group that are also included in table 62 

 are sillimanite-quartz deposits in the Kings Moun- 

 tain district and some andalusite-pyrophyllite-quartz 

 deposits in North Carolina. 



Quartzose deposits of kyanite-group minerals in 

 the Western States are much smaller than those in 

 the Southeastern States. Such deposits are found in 

 New Mexico in the Picuris Range and the Petaca 

 district (Montgomery, 1953; Corey, 1960). An 

 unusual deposit of topaz, sillimanite, and rutile in 

 quartzose gneiss occurs in the Front Range of Colo- 

 rado (Sheridan and others, 1968). In California, 

 kyanite has been mined from quartzose deposits 

 near Ogilby, Imperial County (Henshaw, 1942), and 

 andalusite has been mined at White Mountain, Mono 

 County (Wright, 1957). Dumortierite and andalu- 

 site were once mined from quartzose deposits in 

 altered rhyolite near Oreana, Nev. (Kerr and Jen- 

 ney, 1935). 



BYPRODUCT SOURCES OF KYANITE GROUP MINERALS 



Kyanite and sillimanite occur in small amounts 

 in the sands mined for ilmenite and other heavy 

 minerals in Florida, Georgia, and New Jersey; they 

 have been recovered from the Florida sands since 

 1968 (Browning and others, 1956 ; Markewicz, 1969 ; 

 Cooper, 1970). These minerals are also present in 



very small amounts along with other heavy minerals 

 in the pebble phosphate deposits of Florida ; none of 

 the heavy minerals has been recovered, but Stow 

 (1968) estimated that about 200,000 short tons of 

 heavy minerals (containing about 16 percent kyanite 

 and sillimanite) are discarded yearly from the phos- 

 phate mining operations. Topaz occurs in the molyb- 

 denum ore at Climax, Colo. (Wallace and others, 

 1968) and is a potential byproduct. 



FOREIGN RESOURCES OF KYANITE-GROUP MINERALS 



According to Varley (1965), the minerals of the 

 kyanite group are widely distributed in many coun- 

 tries; the principal deposits of economic value are 

 the quartzose type, as in the United States. Many 

 foreign quartzose deposits contain massive segrega- 

 tions of the AlaSiOs minerals, which in places have 

 accumulated as loose boulders and fragments in the 

 surficial residuum. Such massive ore is easily mined 

 and requires little or no beneficiation, in contrast to 

 domestic disseminated ores. 



India has been the principal foreign producer of 

 AUSiOs minerals since the 1920's, mostly massive 

 kyanite from Lapsa Buru, Singhbhum, Bihar, and 

 massive sillimanite from Assam and Madhya Pra- 

 desh. Sillimanite was once recovered from ilmenite 

 beach placers in Kerala and Madras. The Republic 

 of South Africa has also been a major producer for 

 many years, mining andalusite from river placers 

 in the Marico district, Transvaal, and sillimanite- 

 corundum from near Pella, Namaqualand. Kenya 

 was an important producer of both massive kyanite 

 and kyanite concentrates from 1943 to 1960. Mas- 

 sive kyanite has also been produced from South 

 West Africa, Bechuanaland, Rhodesia, and Nyasa- 

 land. Sillimanite and small amounts of kyanite and 

 andalusite have been produced in Australia since the 

 1930's. In the U.S.S.R., andalusite has been produced 

 on a large scale from quartzose deposits in Kazakh- 

 stan; important deposits of kyanite occur on the 

 Kola Peninsula and of sillimanite, in eastern Siberia. 



Cooper (1970, p. 1062) estimated that foreign re- 

 serves amount to 82,500,000 tons, mainly in the 

 U.S.S.R., the Republic of South Africa, Canada, and 

 India. Resources in the sense used here are clearly 

 far larger and must be enormous in the case of the 

 U.S.S.R., India, and some African countries. The 

 data, howevei; are not adequate for a reliable esti- 

 mate of foreign resources. 



SPECULATIVE RESOURCES 



The AlaSiOs minerals are so common in meta- 

 morphic rocks that they will be continually dis- 

 covered as geologic mapping progresses in meta- 

 morphic terranes in the United States and other 



