MINERALOGY OF DIAMONDS FROM THE JUÍNA KIMBERLITE PROVINCE, SW AMAZON CRATON, BRAZIL: CATHODOLUMINESCENCE, INFRARED SPECTROSCOPY, NITROGEN CONTENT, AND CARBON AND NITROGEN ISOTOPES

DÉBORA P. ARAÚJO, JOSÉ C. GASPAR, YINGWEI FEI, ERIK H. HAURI, RUSSELL HEMLEY
2001 Revista Brasileira de Geociências  
The Mineralogy of 234 primary and alluvial diamonds Iromthc Jufrm Kimberlite Province has been investigated. The majority of diamonds exhibit low CL intensity and typical blue-sky color. Internal features arc rare. The spectral classification of diamonds yields 82% of Type II stones (N-free) and a minor amount of highly aggregated Type I diamonds. sue in Type II diamonds vades Irom -Gto -26.3%0 and in Type I from -3.4 to-13.8%0. o l~N in Type I diamonds ranges from +2.2 to -14Jr'kvand the N
more » ... 4Jr'kvand the N content, from 3.85 to 613.74 at. ppm. e and N isotopic compositions ,U'C compared to worldwide occurrences and to deep diamondassemblages. The incorporation of N by deep diamonds and the contribution ofs ubducrcd terrains of the SW border of the Amazon Cnuon on the formation of the light I'C di.uuonds 1\I'C briefl y discussed.
doi:10.25249/0375-7536.2001314669671 fatcat:ver2sb45dfcmrcsbwmghtsvslm