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Gestoptefontein Farm, Ottosdal, Tswaing Local Municipality, Ngaka Modiri Molema District Municipality, North West, South Africai
Regional Level Types
Gestoptefontein FarmFarm
Ottosdal- not defined -
Tswaing Local MunicipalityMunicipality
Ngaka Modiri Molema District MunicipalityDistrict
North WestProvince
South AfricaCountry

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Latitude & Longitude (WGS84):
26° 43' 58'' South , 25° 59' 40'' East
Latitude & Longitude (decimal):
-26.73278,25.99472
GeoHash:
G#: ke4rzt2y2
GRN:
S18E17
Type:
Farm
Köppen climate type:
BSk : Cold semi-arid (steppe) climate
Nearest Settlements:
PlacePopulationDistance
Wolmaransstad49,366 (2012)51.7km
Mindat Locality ID:
57246
Long-form identifier:
mindat:1:2:57246:7
GUID (UUID V4):
0


Pyrophyllite mine approx 10 km north of Ottosdal. Mined commercially since the 1930's, the pyrophyllite is marketed as Wonderstone and is used for carving and technological applications as it can be readily machined. It is a blue-grey, compact pyrophyllite containing minute needles of rutile and grains of amorphous carbon. On firing at 1200 degrees C the colour changes from grey to pink and the mineralogy changes to an interlocking mass of mullite and rutile with finely dispersed cristobalite. Firing doubles the compression strength of the material.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


1 valid mineral.

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 9 - Silicates
ⓘPyrophyllite9.EC.10Al2Si4O10(OH)2

List of minerals for each chemical element

HHydrogen
Hⓘ PyrophylliteAl2Si4O10(OH)2
OOxygen
Oⓘ PyrophylliteAl2Si4O10(OH)2
AlAluminium
Alⓘ PyrophylliteAl2Si4O10(OH)2
SiSilicon
Siⓘ PyrophylliteAl2Si4O10(OH)2

Other Regions, Features and Areas containing this locality

AfricaContinent
African PlateTectonic Plate
South Africa

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

en.wikipedia.org (n.d.) http://en.wikipedia.org/wiki/Ottosdal
Bosazza, V.L. (1940) Wonderstone - a unique refractory material. Transactions of the British Ceramics Society, Stoke-on-Trent, 1940, Vol. 39, pg. 369-376.
Cairncross, B., Dixon, R. (1995) Minerals of South Africa. Geological Society of South Africa. p.1-290.
Cairncross, Bruce (2004) Field Guide to Rocks & Minerals of Southern Africa. 288pp.
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