Diamonds from Diamantina – MG, Brazil

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A rare feature – hexagonal pitting

Diamonds occur in many colours, shapes, sizes and transparencies. Sometimes they just look like sand (well, expensive, very expensive sand, as a lowly 10 USD/carat stone is worth more than gold – currently hovering 1.200 USD/oz); or else diamonds may be broken (chips), dotted in the inside with other minerals, eroded or pitted at the surface, colourless, slightly tinted or, rarely, fancy (marked tints).

The rough diamonds in this parcel are from the Diamantina region (Jequitinhonha river) in Minas Gerais (Brazil). This is an historic diamond district, originally found and discovered in the early 17th century during Brazil’s colonial period. Diamonds in the area tend to have a greyish tint; alas, this is not their body color (as they would be extremely rare and expensive), just the color of a shallow coating probably due to radiation.

This photo illustrates a rare diamond feature caught by chance on camera. Note the focused diamond on the right hand side; it has a triangular shape (locally know has chapéu de frade). On the center of the diamond there is a depression of rare hexagonal shape, unlike trigons diamond’s characteristic inverted pyramidal pits.

Mineral Occurrences in the South of Portugal (400K scale map)

JUST PUBLISHED BY LNEG

Mineral Occurrences – South of Portugal 400k map

For all those interested in Portuguese mineral deposits, LNEG (the Portuguese Geological Survey), has just released a pdf version of Mineral Occurrences in the South of Portugal (400K scale). With a diverse geology and home to important metallogenic provinces – including but not limited to W, Au, U and complex sulphides Cu, Zn, Pb – Portugal has seem some recent exploration activity by international companies.

To know more look at www.lneg.pt . Drop us a line – luischambel@sinese.pt – if you are interested in investing in Portuguese mineral projects.

LNEG apresenta a Carta de Ocorrências Mineiras do Alentejo e Algarve à Escala 1:400 000

Associação Portuguesa de Geólogos

A partir da informação geológica e mineira disponível nas suas bases de dados o Laboratório Nacional de Energia e Geologia (LNEG) apresenta a Carta de Ocorrências Mineiras do Alentejo e Algarve na escala 1:400 000.
Sobre um fundo geológico simplificado indicam-se 650 ocorrências mineiras referentes a minas em atividade, abandonadas e/ou em fase de fecho e estruturas mineralizadas ainda em pesquisa. Para cada caso é indicado tipo de recurso, a dimensão da ocorrência e o ano de descoberta ou início de mineração. O mapa contempla também 1400 sondagens de prospeção, realizadas desde 1948 e indicadas por classes de profundidade (até 1888 m).
Aceda à versão digital da Carta aqui.
Mais informações aqui.

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Dois leões em África – Uma imagem, mil significados

Dois leões no Congo
Na selva equatorial de Mayoko (Congo)

Até na selva de Mayoko, o Sporting chega (em) primeiro.

Campeão Nacional de Equipas 2013 de Judo em Seniores, Juniores e Cadetes, em primeiro até no futebol no Natal e Ano Novo! Dois leões aproveitam a maré e festejam na selva tropical do coração de África (no Congo, a fronteira do Gabão mesmo ali ao lado).

Cruzam-se aqui muitos caminhos: trabalho, viagens, África, amizade, geologia, tantalite, Portugal, Congo, judo e desporto – claro, o Sporting. Uma imagem, mil significados.

On the up – Angolan diamonds

The report’s latest spin-off has been published in yesterday’s edition of the Mining Journal.
For those of you less patient, the article is only two-pages long.
On the up by Luís Chambel – Look for it in your copy or online.
You can also get the full “One century of Angolan diamonds” here.

Acabou de ser publicado no Mining Journal mais um extrato do relatório sobre a indústria angolana de diamantes.
Para os menos pacientes, o artigo tem apenas duas páginas.
Os assinantes do Mining Journal podem consultar o artigo em papel; a leitura online é outra opção: On the up by Luís Chambel.
Podem, claro, continuar a obter o relatório completo aqui.

Authored by Luís Chambel, with major contributions by Luís Caetano and Manuel Reis, the report is a joint effort of Sínese – Economic Geology and Intelligent Data Analysis and Eaglestone – a financial advisory specialized in Sub-Saharan Africa.

One century of Angolan diamonds – a report

One century of Angolan diamonds

After many months of hard work, the report was released.

The report organizes information about the Angolan diamond industry (the deposits, the mines and prospects, the global market, regulatory and economical settings and the key institutions). This information was previously either disperse, unpublished or only available in Portuguese language sources.

” Angolan diamonds have been known for 100 years. These diamonds are famed for their high quality and high value and have attracted expert buyers from all over the world, from the giant De Beers (the exclusive buyer for many decades) to the smaller scale traders. The country is endowed in both kimberlites and alluvial diamond deposits; many of those deposits still await development. Probably many more deposits still need to be explored and discovered in a territory with a huge potential for diamond.

There is still a road to walk but the last ten years have seen an increasingly stable and growing economy in Angola, with successive elections being certified as free and fair by international organizations and a growing diversified media sector. The business environment has improved and a new mining code has been approved. Transport infrastructure is also being either rebuilt or erected from scratch.

Angola is a land of many opportunities for diamond investors. It has a special business environment and specific risks and challenges; we will guide you through them in this report. We will also discuss the current situation of the international diamond markets and its future trends and the impacts they may have on the Angolan industry. In the end, we hope this report will help you establish a successful venture in this land of promise.

The report has been authored by Luís Chambel, with major contributions by Luís Caetano and Manuel Reis. It is a joint effort by Sínese and eaglestone.

This report will be regularly updated, with major revisions expected annually.

This the is first of several reports on southern Africa the mineral industries.