Figure 10. A map showing the distribution of various categories of diamonds found in Brazil. The name of the mining area is shown (with the abbreviation of the Brazilian state), preceded by its location number on the map.
Figure 9. A simplified map of the major geological regions of Brazil.
Figure 8. Crystals such as this group from the Jequitinhonha River were once used as markers in card games, as they were not recognized as diamonds. Photo by Robert Weldon/GIA, courtesy of Gar Mineração.
Figure A-2. The most common outlines for “brilliant cut” diamonds, as illustrated in A Treatise on Diamonds and Pearls by David Jeffries in 1750. Note that all have 58 facets in a similar layout, and the only differences are their outlines.
Figure 7. This star motif necklace with “Old Mine” cut Brazilian diamonds was made in 1865. Photo by Luisa Oliveira, courtesy of Ajuda National Palace.
Figure A-1. Illustrations of the diamond faceting arrangements known in France by the mid-1700s. These were compiled by Denis Diderot, chief editor from 1745 to 1772 of the 28-volume Encyclopédie, ou Dictionnaire Raisonné des Sciences, des Arts et des Métiers, one of the principal works of the Enlightenment. This page is taken from his 1771 volume entitled Recuiel de Plances, sur Les Sciences, Les Arts Liberauz, et Les Arts Mechaniques (p. 732).
Figure 5. The Estrada Real, or “royal highway,” was the principal 18th century route to transport goods from Minas Gerais to the ports of Parati and Rio de Janeiro, a distance of several hundred miles, for shipment to Europe.
Figure 3. The 1494 Treaty of Tordesilhas effectively divided the South America continent between Portugal and Spain. The Cantino planisphere map, produced around 1502, shows the north-south Tordesilhas meridian line passing through South America, whose geography was still largely unknown. Courtesy of Biblioteca Estense.
Figure 2. This selection of diamonds recovered from the Abaeté River in Minas Gerais, weighing a total of 77.82 carats, is typical of the material being found today in Brazil’s alluvial deposits. Photo by Robert Weldon/GIA, courtesy of Giovani de Deus Borges.
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