 | | Journal (issue) | | Articles 708 Coloured Stone Mining and Trade in Brazil: A Brief History and Current Status By Aurélien...Collection V. L. Villani photo p. 758 Cover Photo: Brazil is the source of a variety of coloured stones,...Gemmology, 35(8), 2017 Gem Notes a b c d cedony (agate), danburite, scapolite, moonstone and kornerupine...Saint-Clair Fonseca Junior (BC Gemas do Brasil, Governador Valadares, Brazil), and heating to 500°C in air was...recently had the pleasure to study two chalcedony/agate cameos that were fascinating for their gemmological |  | | Journal (issue) | | (3) a 1.53 pink diamond from Argyle, courtesy of Rio Tinto; (4) an 11.16 ct sapphire from Madagascar,...market was down to 42% by value and 29% by volume (Rio Tinto Diamonds, 2008). It had unloaded its diamond... PRODUCTION AND MARKETS Rio Tinto. In 2003, London-based mining giant Rio Tinto opened Canada’s second...second diamond mine, Diavik, with 60% ownership. Rio Tinto had established its own rough diamond sales channel...carats over the following several years (Rio Tinto Diamonds, 2006). Rio Tinto marketed its share and its Argyle |
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