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2012 is the year in which Angolan diamonds turn one century. Since the discovery of the first diamonds in 1912 in the Mussulala River - Lunda Norte, Angola has rapidly grown into a major producing country. This report celebrates that fact and describes the Angolan diamond industry’s current situation, its future perspectives and opportunities.
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... Until 1971, Diamang was the only company authorized to explore for and mine diamonds in Angola. It exploited alluvial deposits with great success and, starting in the 1950s, its exploration work led to the discovery of kimberlite deposits such as Catoca, Camatchia, and Camútuè (Chambel, Caetano, and Reis, 2013). More than 40 years after Diamang's replacement by the new state company Endiama, the recent discovery at Luaxe by the Endiama/Alrosa joint venture appears to be the only kimberlite deposit capable of being exploited in Angola so far not found by Diamang. ...
... Study of any map of the distribution of kimberlites in northeast Angola leads to the inescapable conclusion that most of the known kimberlites occur in, or proximal to, river valleys, suggesting that these have been found as a result of having been exposed by erosion and that others lie undiscovered under younger cover (Chambel, Caetano, and Reis, 2013). A number of companies have undertaken airborne geophysical exploration on the uneroded interfluves and some new kimberlites have been found, notably the Mulepe cluster by De Beers, but until the Luaxe discovery nothing of significance had emerged. ...
Southern Africa is generally thought to be well explored, with only limited potential for major new diamond discoveries. However, Chiadzwa in Zimbabwe and reports of a significant new kimberlite find in Angola are testimony to the dangers attached to an attitude that 'there is nothing left to find'. Since the major discoveries in the central interior of South Africa in the 1870s, diamond exploration in the region has been led by market and political factors that influence the key exploration drivers of opportunity and value proposition. Unexpected new discoveries by new players always impact on existing producers and, from time to time, denial of opportunity through political or protectionist policies has inhibited investment in exploration. Entrepreneurial exploration appetite in southern Africa will be tempered by the potential value equation and security of investment. Overlaid on this, developments in diamond recovery technologies provide opportunity to reinvigorate current mines and old prospects previously considered too difficult or costly to exploit. Position on the cost curve will remain a key factor for survival in an increasingly competitive environment.Southern Africa is generally thought to be well explored, with only limited potential for major new diamond discoveries. However, Chiadzwa in Zimbabwe and reports of a significant new kimberlite find in Angola are testimony to the dangers attached to an attitude that 'there is nothing left to find'. Since the major discoveries in the central interior of South Africa in the 1870s, diamond exploration in the region has been led by market and political factors that influence the key exploration drivers of opportunity and value proposition. Unexpected new discoveries by new players always impact on existing producers and, from time to time, denial of opportunity through political or protectionist policies has inhibited investment in exploration. Entrepreneurial exploration appetite in southern Africa will be tempered by the potential value equation and security of investment. Overlaid on this, developments in diamond recovery technologies provide opportunity to reinvigorate current mines and old prospects previously considered too difficult or costly to exploit. Position on the cost curve will remain a key factor for survival in an increasingly competitive environment. © 2019 The Southern African Institute of Mining and Metallurgy.
... National and provincial boundaries are in black. White circles represent kimberlites after aforementioned sources and white stars represent exploited alluvial diamond deposits in 2013 (after Chambel et al., 2013). Areas of alluvial diamond concentration (in blue) after Dietrich (2000). ...
Alluvial diamonds from the Kasai River, Democratic Republic of the Congo (DRC) are sourced from Cretaceous kimberlites of the Lucapa graben in Angola. Analysis of 40 inclusion-bearing diamonds provides new insights into the characteristics and evolution of ancient lithospheric mantle of the Congo craton. Silicate inclusions permitted us to classify diamonds as peridotitic, containing Fo91–95 and En92–94, (23 diamonds, 70% of the suite), and eclogitic, containing Cr-poor pyrope and omphacite with 11–27% jadeite (6 diamonds, 18% of the suite). Fluid inclusion compositions of fibrous diamonds are moderately to highly silicic, matching compositions of diamond-forming fluids from other DRC diamonds. Regional homogeneity of Congo fibrous diamond fluid inclusion compositions suggests spatially extensive homogenization of Cretaceous diamond forming fluids within the Congo lithospheric mantle. In situ cathodoluminescence, secondary ion mass spectrometry and Fourier transform infrared spectroscopy reveal large heterogeneities in N, N aggregation into B-centers (NB), and δ13C, indicating that diamonds grew episodically from fluids of distinct sources. Peridotitic diamonds contain up to 2962 ppm N, show 0–88% NB, and have δ13C isotopic compositions from − 12.5‰ to − 1.9‰ with a mode near mantle-like values. Eclogitic diamonds contain 14–1432 ppm N, NB spanning 29%–68%, and wider and lighter δ13C isotopic compositions of − 17.8‰ to − 3.4‰. Fibrous diamonds contain more N (up to 2976 ppm) and are restricted in δ13C from − 4.1‰ to − 9.4‰. Clinopyroxene-garnet thermobarometry suggests diamond formation at 1350–1375 °C at 5.8 to 6.3 GPa, whereas N aggregation thermometry yields diamond residence temperatures between 1000 and 1280 °C, if the assumed mantle residence time is 0.9–3.3 Ga. Integrated geothermobaromtery indicates heat fluxes of 41–44 mW/m2 during diamond formation and a shallow lithosphere-asthenosphere boundary (LAB) at 190–210 km. The hotter mantle may be attributable to contemporaneous rifting of the southern Atlantic, multiple post-Archean reactivations of the craton, and/or proximal Cretaceous plumes.
From the discovery of diamonds in South Africa in 1866 until the end of 2013, Africa is estimated to have produced almost 3.2 Bct out of a total global production of 5.03 Bct, or 63.6% of all diamonds that have ever been mined. In 2013 African countries ranked 2nd (Botswana), 3rd (DRC), 6th (Zimbabwe), 7th (Angola), 8th (South Africa), and 9th (Namibia), in terms of carat production and 1st (Botswana), 4th (Namibia), 5th (Angola), 6th (South Africa), 7th (Zimbabwe), and 9th (DRC), in terms of value of the diamonds produced. In 2013 Africa produced 70.6 Mct out of a global total of 130.5 Mct or 54.1%, which was valued at US$ 8.7 billion representing 61.5% of the global value of US$ 14.1 billion.
