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Koffiefontein Mine, Koffiefontein, Xhariep District, Free State, South Africai
Regional Level Types
Koffiefontein MineMine
Koffiefontein- not defined -
Xhariep DistrictDistrict
Free StateProvince
South AfricaCountry

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Latitude & Longitude (WGS84): 29° 23' 59'' South , 25° 1' 0'' East
Latitude & Longitude (decimal): -29.40000,25.01667
GeoHash:G#: kdcb9rbsd
Owned/operated by:Petra Diamonds Ltd (100%)
Locality type:Mine
Köppen climate type:BSk : Cold semi-arid (steppe) climate



A diamond mine in a kimberlite pipe.

Diamonds were first discovered on the Koffiefontein farm in 1870. A few diggers investigated the property but it was soon abandoned due to the discovery of the richer pipes 110km to the North on the De Beers farm.

Mining re-started in 1878 the form of 1,700 small claims that were later (1894) amalgamated into Koffiefontein Mine Limited, a company established by Alfred Moseley, a London diamond merchant.

De Beers acquired control of Koffiefontein Mine Limited in 1911. Mining operations were then continuous until the advent of the Great Depression in 1932 when work was suspended.

Between 1950 and 1953, a prospecting shaft was sunk which was followed by limited production. The mine was reopened in 1970 and preparations for increased production were completed in August 1971. Immediately after completing the preparations, production from the open pit commenced and proceeded to a depth of 270 metres.

Underground development started in 1974 through a sampling programme. Underground production briefly took place in 1982 but ceased soon thereafter due to the 1981 slump in the diamond market, before resuming again in March 1987. In February 2006, De Beers ceased mining when the old order mining right for Koffiefontein expired and in July of that year Petra Diamonds commenced operating the mine under care and maintenance conditions, before completing the acquisition of the mine in July 2007.

From its first beginnings, Koffiefontein has been noted for the excellent quality of its diamonds, with Edwin Streeter commenting in 1898 that its diamonds were of the “first water” (meaning of exceptional clarity).

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.


Mineral List


4 valid minerals. 1 (TL) - type locality of valid minerals.

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!

Select Rock List Type

Alphabetical List Tree Diagram

Detailed Mineral List:

Diamond
Formula: C
Reference: Mining Ann. Review (1985): 147.
'commodity:Diamond'
Reference:  
Diopside
Formula: CaMgSi2O6
Reference: Mathias, M., Siebert, J.C., and Rickwood, P.C. (1970): Contributions to Mineralogy and Petrology 26, 75-123.
Diopside var: Chromian Diopside
Formula: Ca(Mg,Cr)Si2O6
Reference: Mathias, M., Siebert, J.C., and Rickwood, P.C. (1970): Contributions to Mineralogy and Petrology 26, 75-123.
'Fayalite-Forsterite Series'
Reference: Field, M., Stiefenhofer, J., Robey, J., and Kurszlaukis, S. (2008): Ore Geology Reviews 34, 33-75.
'Garnet Group'
Formula: X3Z2(SiO4)3
Reference: Mathias, M., Siebert, J.C., and Rickwood, P.C. (1970): Contributions to Mineralogy and Petrology 26, 75-123.
Goldschmidtite (TL)
Formula: KNbO3
Type Locality:
Reference: Meyer, N.A., Wenz, M.D., Walsh, J.P.S., Jacobsen, S.D., Locock, A.J. and Harris, J.W. (2018) Goldschmidtite, IMA 2018-034. CNMNC Newsletter No. 44, August 2018, page xxx; Mineralogical Magazine: 82: xxx–xxx.
'Kimberlite'
Reference: mindat.org
Periclase
Formula: MgO
Reference: Field, M., Stiefenhofer, J., Robey, J., and Kurszlaukis, S. (2008): Ore Geology Reviews 34, 33-75.
Periclase var: Ferropericlase
Formula: (Mg,Fe)O
Reference: Field, M., Stiefenhofer, J., Robey, J., and Kurszlaukis, S. (2008): Ore Geology Reviews 34, 33-75.

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
Diamond1.CB.10aC
Group 4 - Oxides and Hydroxides
Periclase4.AB.25MgO
var: Ferropericlase4.AB.25(Mg,Fe)O
Group 9 - Silicates
Diopside9.DA.15CaMgSi2O6
var: Chromian Diopside9.DA.15Ca(Mg,Cr)Si2O6
Unclassified Minerals, Rocks, etc.
Fayalite-Forsterite Series-
Garnet Group-X3Z2(SiO4)3
Goldschmidtite (TL)-KNbO3
Kimberlite-

List of minerals arranged by Dana 8th Edition classification

Group 1 - NATIVE ELEMENTS AND ALLOYS
Semi-metals and non-metals
Diamond1.3.6.1C
Group 4 - SIMPLE OXIDES
AX
Periclase4.2.1.1MgO
Group 65 - INOSILICATES Single-Width,Unbranched Chains,(W=1)
Single-Width Unbranched Chains, W=1 with chains P=2
Diopside65.1.3a.1CaMgSi2O6
Unclassified Minerals, Rocks, etc.
var: Chromian Diopside-Ca(Mg,Cr)Si2O6
'Fayalite-Forsterite Series'-
'Garnet Group'-X3Z2(SiO4)3
Goldschmidtite (TL)-KNbO3
'Kimberlite'-
Periclase
var: Ferropericlase
-(Mg,Fe)O

List of minerals for each chemical element

CCarbon
C DiamondC
OOxygen
O Diopside (var: Chromian Diopside)Ca(Mg,Cr)Si2O6
O DiopsideCaMgSi2O6
O Periclase (var: Ferropericlase)(Mg,Fe)O
O Garnet GroupX3Z2(SiO4)3
O GoldschmidtiteKNbO3
O PericlaseMgO
MgMagnesium
Mg Diopside (var: Chromian Diopside)Ca(Mg,Cr)Si2O6
Mg DiopsideCaMgSi2O6
Mg Periclase (var: Ferropericlase)(Mg,Fe)O
Mg PericlaseMgO
SiSilicon
Si Diopside (var: Chromian Diopside)Ca(Mg,Cr)Si2O6
Si DiopsideCaMgSi2O6
Si Garnet GroupX3Z2(SiO4)3
KPotassium
K GoldschmidtiteKNbO3
CaCalcium
Ca Diopside (var: Chromian Diopside)Ca(Mg,Cr)Si2O6
Ca DiopsideCaMgSi2O6
CrChromium
Cr Diopside (var: Chromian Diopside)Ca(Mg,Cr)Si2O6
FeIron
Fe Periclase (var: Ferropericlase)(Mg,Fe)O
NbNiobium
Nb GoldschmidtiteKNbO3

Regional Geology

This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.

Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org

Jurassic - Permian
145 - 298.9 Ma



ID: 3309804

Age: Phanerozoic (145 - 298.9 Ma)

Lithology: Sedimentary (karoo)

Reference: Thiéblemont, D. (ed.). New edition of the 1:10,000,000 geological map of Africa. CGMW-BRGM. [190]

Permian
251.902 - 298.9 Ma



ID: 2234951
Volksrust Formation of Ecca Group of Karoo Supergroup

Age: Phanerozoic (251.902 - 298.9 Ma)

Stratigraphic Name: Volksrust Formation

Description: Mudrock

Reference: Council for Geoscience. Geologic map of South Africa, 1:1M. National Science Councils of South Africa. [41]

Permian
251.902 - 298.9 Ma



ID: 3189153
Paleozoic sedimentary rocks

Age: Phanerozoic (251.902 - 298.9 Ma)

Stratigraphic Name: Karoo Supergroup

Comments: Karoo Basin

Lithology: Sedimentary rocks

Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. [154]

Data and map coding provided by Macrostrat.org, used under Creative Commons Attribution 4.0 License

References

Sort by

Year (asc) Year (desc) Author (A-Z) Author (Z-A)
Mathias, M., Siebert, J.C., and Rickwood, P.C. (1970): Some Aspects of the Mineralogy and Petrology of Ultramafic Xenoliths in Kimberlite. Contributions to Mineralogy and Petrology 26, 75-123.
Mining Annual Review (1985): 147.
Izraeli, E.S., Harris, J.W., and Navon, O. (2004): Fluid and mineral inclusions in cloudy diamonds from Koffiefontein, South Africa. Geochmica et Cosmochimica Acta: 68: 2561-2575.
Field, M., Stiefenhofer, J., Robey, J., and Kurszlaukis, S. (2008): Kimberlite-hosted diamond deposits of southern Africa: A review. Ore Geology Reviews 34, 33-75.

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