Source: https://www.mindat.org/loc-3438.html
Timestamp: 2019-04-22 22:37:34+00:00

Document:
Boron is a small town in the Kramer district about midway between the larger towns of Mojave to the West and Barstow in the east. Many of the workers in the big U.S. Borax open pit mine a little north of town live here. For many years borax and Kernite were mined from underground workings and at the time the open pit mine was started ~1958, it was the largest underground working in California with more than 200 miles of tunnels. Few specimens were produced from the underground workings compared to what has been produced from the open pit operation. The majority of the specimens are specimens of Colemanite crystals that were encountered just after the overburden of alluvial material had been removed from the top of the deposit and the altered cap of the borate ore body was exposed. This altered cap consisted mostly of Colemanite and Ulexite and was often quite full of crystals pockets. Other minerals like Kurnakovite, Inderite, Tunellite, and Hydroboracite were also encountered. For several years, collectors were allowed to collect freely on the dumps and during this time thousands of specimens of various borate minerals were collected. Now the mine and its dumps are off limits to collectors except on rare carefully controlled occasions, usually for the little annual Boron gem and mineral show. The mine, its extensive dumps and its borate processing and production facility are continuously patrolled by security guards. Over the years there have been a few rather extensive labor disputes and this in addition to the litigious nature of American society have added to the security concerns of the company. There is however a very nice visitors center that the mine has built that overlooks the big open pit operation and an interesting video presentation is available for viewing in their small auditorium along with other historical exhibits that include one of the original 20 mule team wagon trains. Usually, there is a pile of borate minerals that is periodically dumped in the parking lot of the visitors center where visitors can load up on high-grade Kernite and sometimes low-grade specimens of Ulexite and Colemanite.
85 valid minerals. 4 (TL) - type locality of valid minerals.
Description: Occurs as subhedral to anhedral grains in the tuff beds bordering the main sodium borate beds.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9&10): 146; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 360.
Description: Constituent of phosphatic material of fossil bones.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9&10): 146; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 315.
Description: Comprises fossil shells in shales underlying the borate deposit.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9&10): 146; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 215.
Description: Occurs sparingly as small rounded grains or subhedral crystals on fibrous ulexite.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9): 146; Carnahan, V. (1970), Notes on some minerals from Boron: Bulletin of the Mineralogical Society of Southern California, November: 10; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 213.
Description: Occurs as minute grains and octahedral crystals.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9): 147; Carnahan, V. (1970), Notes on some minerals from Boron: Bulletin of the Mineralogical Society of Southern California, November: 10; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 186.
Description: Occurs as tabular crystals to 3 mm long and microscopic spikes on colemanite.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9&10): 147; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 292.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9&10): 147, 172; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 222.
Description: Occurs with opal as fracture coatings in sandy clay of the Ricardo Formation.
Reference: Walker, G.W., Lovering, T.G., and Stephens, H.G. (1956), Radioactive Deposits in California: Special Report 49 of the California Division of Mines & Geology: 19; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 326.
Description: Found in the Saddleback basalt that lies under the deposit. Found in vugs as free standing micro crystals.
Description: Occurs as silky, curling, fibrous crystals.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9&10): 152; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 266.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9&10): 152; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 286.
Description: Occurs poorly developed in the open pit.
Description: Occurs as scaly masses and incrustations in clay surrounding the deposit.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9&10): 152; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 191.
Description: Material has a high Li content.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9&10): 165; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 439.
Description: Occurs in claystone and in basalt float.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9): 152; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 161.
Description: Occurs as a thin glassy coating on joint-crack surfaces of basalt.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9): 152, 165, 168; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 66, 438; Cal Div of Mines & Geology "Mineral Information Service: 22(9) (Sept 1969).
Description: Basaltic; elongate crystals in ulexite.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9&10): 152; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 401.
Description: Occurs as crystals to 1.5 mm in vesicles of basalt float.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9&10): 152; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 385.
Description: Occurs as grains in the siltstone bed.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9): 152; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 171.
Description: Occurs as remnants of euhedral and subhedral grains being replaced by borax in borax crystals and massive borates.
Reference: Bowser, C.J. (1965a), Geochemistry and petrology of the sodium borates in the non-marine evaporative environment: Unpublished Ph.. dissertation, University of California, Los Angeles, 307 pp.: 137, 267-268; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 360.
Description: Kurnakovite has been found at Boron in free standing crystals in excess of 30 cm and in clusters more than 60 cm across. It is typically found associated with the gray green mud found at the deposit and dense fibrous balls of white ulexite. Rarely it is found associated with prismatic crystals of inderite. The crystals are typically white and transparent with inclusions of the gray/green mud of the deposit. Several different crystal habits have been noted. The crystals were found only once during a short period early in the development of the large open pit mine at Boron. In the polluted air of Los Angeles, kurnakovite crystals develop a white patina that can be washed off with water. Kurnakovite is quite heat sensitive, especially the larger crystals and the temperature of the kurnakovite and the water should be allowed to equilibrate before washing the specimen.
Description: Occurs as a powdery alteration of hypersthene in basalt float in the overburden of the deposit.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9): 165-166; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 162.
Reference: American Mineralogist (2005): 90: 1186-1191; Tschernich, R. (1992): Zeolites of the World: 64.
Description: Occurs as micro-particles of highly magnetic material disseminated throughout the clay-shale portion of the deposit. Occurs in nodules of kurnakovite and colemanite above the main orebody.
Description: Occurs as a thin black coating on a specimen of clay.
Reference: Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 115.
Description: The second most abundant clay at the deposit.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9&10): 152; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 427.
Description: Occurs as crystals to 1 mm long in vesicles of red basalt float.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9): 165-166; Carnahan, V. (1970), Notes on some minerals from Boron: Bulletin of the Mineralogical Society of Southern California, November: 10; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 174.
Description: Occurs as minute cubes in joint cracks in a dense black basalt underlying the deposit. Also occurs as minute brassy crystals in nodules and geodes of calcite.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9): 166; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 72; California Division of Mines & Geology: Mineral Information Service: 22(10) (Oct 1969).
Reference: Chenard, G., and Chenard, D. 1962 Kern County Agate: Lapidary Journal, v. 16, no. 1, p. 106-107.
Description: Occurs as efflorescent clusters of needle-like crystals to 1.5 mm.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9&10): 168; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 278-279.
Description: Occurs as masses of fibers to 2.5 cm (1 inch).
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9&10): 169; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 218.
Description: Occurs as minute crystals in the main orebody.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9): 169; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 52.
Reference: Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9): 168; Carnahan, V. (1970), Notes on some minerals from Boron: Bulletin of the Mineralogical Society of Southern California, November: 10.
Reference: Erd, R.C., Morgan, V., and Clark, J.R. (1961) Tunellite, a new hydrous strontium borate from the Kramer Borate District, California. U.S. Geological Survey Professional Paper, 424-C, 294-297.; Speckels, M.L. (1965) Minerals for everyone: the complete guide to micromounts. Gembooks, Mentone, California.
Description: Occurs on montmorillonite as clusters of minute crystals at the bottom of the pit.
Reference: Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 243.
Description: Alluvium, lake, playa, and terrace deposits; unconsolidated and semi-consolidated. Mostly nonmarine, but includes marine deposits near the coast.
Chenard, G. and Chenard, D. (1962) Kern County Agate. Lapidary Journal, 16(1), 106-107.
Gems & Minerals (1966) 343, 26.
American Mineralogist (1971) 56, 1057.
Mineralogical Record (1971) 2, 37.
Currier, Rock (2010) personal communication to Mindat.org.

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