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Kalahari manganese field, Northern Cape Province, South Africa

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Location is approximate, estimate based on other nearby localities.
 
Latitude & Longitude (WGS84): 27° South , 22° East (est.)
Margin of Error:~17km
Other regions containing this locality:Kalahari Desert, Africa
Köppen climate type:BSh : Hot semi-arid (steppe) climate


The Kalahari Manganese Field

Situated in extremely well-preserved, 2.2 billion-year-old sedimentary rocks of the Transvaal Supergroup near Hotazel in the Northern Cape province of South Africa, the Kalahari Manganese Field is one of the geological and mineralogical wonders of the world. In addition to representing by far the largest-known land-based manganese deposit on Earth, the Kalahari Manganese Field is also the world’s top producer of ore in manganese metal tonnage. It also hosts a world-renowned, unique and varied assemblage of aesthetic collector’s mineral specimens that are often rare or unique.

Rhodochrosite

The mineral that made the Kalahari Manganese Field world famous was rhodochrosite. This mineral was originally discovered in the Hotazel opencast mine in 1963. These early specimens were generally not spectacular and consist mainly of drusy rhodochrosite associated with gypsum. Up until 1967, however, a few scalenohedral crystals did emerge from Hotazel mine. Then, 10 years later, the major discovery of rhodochrosite was made while N’Chwaning I mine was being opened, when a wide variety of the different colours and habits of spectacular specimens was encountered. Apart from its colour variations, which range from wine-red to pale-pink, the rhodochrosite occurs in a variety of shapes and sizes, from ‘dog-tooth’ (scalenohedral) to smooth spheres and ‘wheat-sheaf’ bundles of crystals.

The shaft of N’Chwaning I mine penetrated directly into vugs containing crystals, and hundreds of loose crystals were swept away off the floor at that time.

Truly exceptional, undamaged rhodochrosites are not that common, particularly the scalenohedral form, whose terminations cleave off very easily. Gem-quality material has been faceted. Most of the high-quality rhodochrosite came from N’Chwaning I mine. Specimens from Hotazel and N’Chwaning I mines typically occur with manganite, gypsum, todorokite, chalcedony and drusy quartz. The origin and formation of the rhodochrosite is connected to relatively recent geological events in the Kalahari Manganese Field and bears no link to the major Wessels-type alteration period that took place over a billion years ago. This rhodochrosite, from this much older geological event, is found in both N’Chwaning and Wessels mines but is less spectacular, and consists almost exclusively of simple pink, rhombohedral crystals, less than one centimetre, sometimes associated with gageite, orlymanite, caryopilite and leucophoenicite.
Drusy pink rhodochrosite was the most common mineral found associated with the 2006 N’Chwaning I mine shigaite specimens. Most have drusy, pale-pink to pink interlocking rhodochrosite crystals, one to three millimetres long. Some specimens have translucent pink crystals up to one centimetre or slightly longer, but these tend to be isolated on the drusy matrix. One variation of the pink rhodochrosite is thin, prismatic needle-like crystals up to two centimetres, which are intergrown with each other. These crystals are transparent, pale-red and bicoloured, almost always with a darker, red-brown colour at the termination of the crystals.

In early 2006, a very small discovery of rhodochrosite was made at N’Chwaning II mine, probably fewer than three or four dozen specimens. The difference from the classic Kalahari rhodochrosite is that this small pocket yielded pink, curved rhombohedrons, up to one centimetre. Matrix specimens coated with these crystals were collected, the largest being 12cm. (Cairncross and Beukes, 2013).

Mineral List

Mineral list contains entries from the region specified including sub-localities

Aegirine

Aegirine-augite

var: Blanfordite

Afwillite

Åkermanite

Albite

Andradite

var: Hydroandradite

Ankerite

'Apatite'

'Apophyllite'

Aragonite

Azurite

Banalsite

Baryte

Bementite

Birnessite

Bixbyite

'Bloodstone'

Bornite

Brandtite

Braunite

'Braunite-II' (FRL)

Brucite

Bultfonteinite

Bustamite

Cairncrossite (TL)

Calcite

Caryopilite

Celestine

Chalcocite

Chalcophanite

Chalcopyrite

Chamosite

Charlesite

'Chlorite Group'

Chrysocolla

Cinnabar

Clinochlore

'Clinochrysotile'

Clinotobermorite

Clinozoisite

Colinowensite (TL)

Copper

Creedite

Cryptomelane

Cymrite

Cyprine (TL)

Datolite

Despujolsite

Diaspore

var: Mangan-diaspore

Diegogattaite (TL)

Diopside

Dolomite

Effenbergerite (TL)

Ephesite

Epidote

Ettringite

Feitknechtite

'Ferro-akermanite'

Ferrobustamite

Fluorapatite

Foshagite

Friedelite

Gageite

'Gageite-2M'

Galena

Gatehouseite

Gaudefroyite

Glaucochroite

Glauconite

Goethite

Gonyerite

Gowerite

Greenalite

Grossular

var: Hibschite

'Grossular-Hibschite Series'

Groutite

Guidottiite (TL)

Gypsum

Hausmannite

Hematite

Hennomartinite (TL)

Henritermierite

Hollandite

Holtstamite (TL)

Hydroxyapophyllite-(K)

Inesite

Inyoite

Jacobsite

Jennite

Johannsenite

Jouravskite

Kaolinite

Kenotobermorite (TL)

'Kenotobermorite-4O'

Kentrolite

Kirschsteinite

Kutnohorite

Lavinskyite (TL)

Lepidocrocite

Leucophoenicite

Lipuite (TL)

Lithiophorite

Lizardite

Magnesio-arfvedsonite

Magnetite

Malachite

'Manganese'

'Manganese Oxides'

Manganite

'Manganoan Calcite'

Manganvesuvianite (TL)

Manjiroite

Marcasite

Marokite

Marshallsussmanite (TL)

Meieranite (TL)

Minnesotaite

Mozartite

Natrolite

Nchwaningite (TL)

Neltnerite

Nontronite

Norrishite

Nsutite

Olmiite (TL)

Opal

Orientite

Orlymanite (TL)

Oyelite

Pargasite

Parsettensite

'Partridgeite'

Pectolite

Phlogopite

Piemontite

Piemontite-(Sr)

Poldervaartite (TL)

Portlandite

Potassic-mangani-leakeite (TL)

Prehnite

Pyrite

Pyrochroite

Pyrolusite

Pyrophanite

Quartz

var: Amethyst

var: Chalcedony

var: Jasper

Ramsdellite

Ranciéite

Rhodochrosite

Rhodonite

Richterite

Riebeckite

Romanèchite

Ruizite

Saponite

Scottyite (TL)

Serandite

'Serpentine Subgroup'

Shigaite

Siderite

Sogdianite

Sphalerite

Stevensite

Stilpnomelane

Strontianite

Strontioruizite (TL)

Sturmanite

Sugilite

Sussexite

Taikanite

Talc

Taniajacoite (TL)

Tephroite

Tetraferriannite

Thaumasite

Thomsonite-Ca

Titanite

Tobermorite

Todorokite

Tremolite

Tridymite

Tweddillite (TL)

Vaterite

Vesuvianite

Vonbezingite (TL)

Vuagnatite

'Wad'

Wesselsite (TL)

Wollastonite

Xonotlite

Zoisite


174 valid minerals. 25 (TL) - type locality of valid minerals. 1 (FRL) - first recorded locality of unapproved mineral/variety/etc.

Rock Types Recorded

Note: this is a very new system on mindat.org and data is currently VERY limited. Please bear with us while we work towards adding this information!

Rock list contains entries from the region specified including sub-localities

Select Rock List Type

Alphabetical List Tree Diagram

Geochronology

Mineralization age: Stenian : 1040 Ma to 1010 Ma

Important note: This table is based only on rock and mineral ages recorded below and is not necessarily a complete representation of the geochronology, but does give an indication of possible mineralization events relevant to this locality. As more age information is added this table may expand in the future. A break in the table simply indicates a lack of data entered here, not necessarily a break in the geologic sequence. Grey background entries are from different, related, localities.

Geologic TimeRocks, Minerals and Events
Precambrian
 Proterozoic
  Mesoproterozoic
   Stenian
ⓘ Norrishite (youngest age)1010 MaWessels Mine (Wessel's Mine), Hotazel, Kalahari manganese field, Northern Cape Province, South Africa
ⓘ Norrishite (oldest age)1040 MaWessels Mine (Wessel's Mine), Hotazel, Kalahari manganese field, Northern Cape Province, South Africa

Localities in this Region


This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
De Villiers, P.R. (1970). The geology and mineralogy of the Kalahari manganese-field north of Sishen, Cape Province. Memoir of the Geological Survey of South Africa, No. 59, 84 pages.
De Villiers, P. R., (1971). The geology and mineralogy of the Kalahari manganese-field north of Sishen, Cape Province. Geological Survey of South Africa, Memoir 59, 84 pages.
S.A. Manganese Corporation SAMCOR Ltd. (1977). Kalahari Wealth, the Story of Manganese. Purnell, Cape Town, 174 pages.
Wilson, W.E. & Dunn, P.J., (1978) Famous localities: The Kalahari manganese field. Mineralogical Record, 9(3), 137-153.
Kleyenstüber, A.S.E. (1982). A review of the geology and mining of the Kalahari manganese field. In: Glen, H.W. (editor). Proceedings, 12th CMMI Congress. Geological Society of South Africa, Johannesburg, 213–220.
Pienaar, H.S. (1982). Gem quality friedelite from the Kalahari manganese field near Kuruman, South Africa. Gems and Gemology, 18, 221–224.
Miyano, T. and Beukes, N.J. (1987). Physicochemical environments for the formation of quartz-free manganese oxide ores from the Early Proterozoic Hotazel Formation, Kalahari manganese field, South Africa. Economic Geology, 82, 706–718.
Miyano, T. and Beukes, N.J. (1988). Estimation of carbon dioxide fugacity and braunite II stability in quartz-free manganese oxide ores from the Kalahari manganese field, South Africa. South African Journal of Science, 84, 244–246.
Von Bezing, L., Dixon, R.D., Pohl, D. and Cavallo, G. (1991). The Kalahari manganese field: An update. Mineralogical Record, 24(4), 10–27.
Kleyenstüber, A.S.E. (1993). Some significant characteristics of the manganese ores and some of the minerals occurring in the Proterozoic Kalahari manganese field, South Africa. Resource Geology, 17, 2–11.
Von Bezing, L. and Gutzmer, J. (1994a). Das Kalahari Manganerzfeld und seine Mineralien (Teil I). Mineralien Welt, 4, 24–46.
Von Bezing, L. and Gutzmer, J. (1994b). Das Kalahari Manganerzfeld und seine Mineralien (Teil II). Mineralien Welt, 5, 41–59.
Cairncross, B. and R. Dixon (1995) Minerals of South Africa.
Cornell, D.H. and Schütte, S.S. (1995). A volcanic-exhalative origin for the world’s largest (Kalahari) manganese field. Mineralium Deposita, 30, 146–151.
Gutzmer, J. and Beukes, N.J. (1995). Fault controlled metasomatic alteration of Early Proterozoic sedimentary manganese ores in the Kalahari manganese field, South Africa. Economic Geology, 90, 823–844.
Gutzmer, J., Beukes, N.J., Kleyenstüber, A.S.E. and Burger, A.M. (1995). Magnetic hausmannite from hydrothermally altered manganese ore in the Palaeoproterozoic Kalahari manganese deposit, Transvaal Supergroup, South Africa. Mineralogical Magazine, 59, 703–716.
Gutzmer, J. (1996). Genesis and alteration of the Kalahari and Postmasburg manganese deposits, Griqualand West, South Africa. PhD thesis (unpublished). Rand Afrikaans University, Johannesburg, 266 pages.
Gutzmer, J. and Beukes, N.J. (1996). Mineral paragenesis of the Kalahari manganese field, South Africa. Ore Geology Reviews, 11, 405–428.
Cairncross, B., Beukes, N. and Gutzmer, J. (1997) The Manganese Adventure – The South African Manganese Fields. Associated Ore & Metal Corporation Limited, Johannesburg, Republic of South Africa.
Gutzmer, J., Beukes, N.J. and Yeh, H-W. (1997). Metasomatic and supergene fault-controlled alteration of Early Proterozoic sedimentary manganese ore at Mamatwan Mine, Kalahari manganese field, South Africa. South African Journal of Geology, 100, 53–71.
Tsikos, H. and Moore, J.M. (1997). Petrography and geochemistry of the Paleoproterozoic Hotazel Iron-Manganese Formation, Kalahari Manganese Field, South Africa: Implications for Precambrian manganese metallogenesis. Economic Geology, 92, 87–97.
Tsikos, H. and Moore, J.M. (1998). The Kalahari manganese field: An enigmatic association of iron and manganese. South African Journal of Geology, 101, 287–290.
Lüders, V., Gutzmer, J., Beukes, N.J. (1999). Formation of high-grade manganese ores in the Kalahari Manganese Field, South Africa: Evidence from fluid inclusions studies in co-genetic iron and manganese oxides, and gangue minerals. In: Stanley et al. (editors). Mineral Deposits: Processes to Processing. Balkema, Rotterdam, 55–58.
Cairncross, B. and Gutzmer, J. (2000). Spektakulärer Mineralien aus dem Kalahari Manganerzfeld, Südafrika. Lapis, 25, No. 10, 13–26.
Gutzmer, J. and Beukes, N.J. (2000). Asbestiform manjiroite and todorokite from the Kalahari manganese field, South Africa. South African Journal of Geology, 103, 163–174.
Cairncross, B. and Gutzmer, J. (2000). Spektakulärer Mineralien aus dem Kalahari Manganerzfeld, Südafrika. Lapis, 25, No. 10, 13–26.
Steyn, P.H.R. (2000). Changing tides: the story of ASSMANG. Associated Manganese Mines of South Africa, Johannesburg, 274 pages.
Evans, D.A.D., Gutzmer, J., Beukes, N.J., Kirschvink, J.L. (2001). Paleomagnetic constraints on ages of mineralization in the Kalahari manganese field, South Africa. Economic Geology, 96, 621–631.
Gutzmer J. and Cairncross, B. (2001). Seltene mineralien aus dem Kalahari-Manganerzfeld, Südafrika. Lapis, 26, No. 10, 32–42.
Cairncross, B. and Balayer, P. (2007). Neufund: Shigait aus den Kalahari-Manganfeldern, Südafrika. Lapis, 32, 23–26.
Gutzmer, J. and Cairncross, B. (2002). Spectacular minerals from the Kalahari manganese field, South Africa. Rocks & Minerals – Special Issue on ‘Minerals of Africa’, 77, 94–107.
Tsikos, H., Beukes, N.J., Moore, J.M. and Harris, C., (2003). Deposition, diagenesis and secondary enrichment of metals in the Paleoproterozoic Hotazel Iron Formation, Kalahari manganese field, South Africa. Economic Geology, 98, 1149–1462.
Gutzmer, J., Du Plooy, A.P. and Beukes, N.J. (2012). Timing of supergene enrichment of low-grade manganese ores in the Kalahari Manganese Field South Africa. Ore Geology Reviews, 47, 136-153.
Cairncross, B., Beukes, N. J. (2013): The Kalahari Manganese Adventure – The Adventure Continues. Random House Struik, Capetown, Republic of South Africa, 384 pp.
Blignaut, L. (2017). A Petrographical and Geochemical Analysis of the Upper and Lower Manganese Ore Bodies from the Kalahari Manganese Deposit, Northern Cape, South Africa – Controls on Hydrothermal Metasomatism and Metal Upgrading. PhD thesis, Department of Geology, University of Johannesburg, South Africa, 348 pages.

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