Morfologia cristalina de diamantes provenientes das regiões de Chapada dos Guimarães, Poxoréu, Paranatinga, Diamantino e Alto Paraguai, Mato Grosso

This paper presents the main results of a mineralogical investigation carried out on detritic diamonds from the municipalities of Chapada dos Guimaraes, Poxoreu, Paranatinga, Diamantino and Alto Paraguai, in the state of Mato Grosso, Brazil. The main features observed were the dominance of rounded dodecahedral crystals, followed by cleavage fragments, irregular forms and aggregates. Less frequent morphological types included octahedral, transitional forms between the flat octahedral and the rounded dodecahedral, flat twins, cube, pseudohexatetraedral, as well as some pollycrystaline diamonds (carbonado and ballas).