VKC April 2022 - Roy Bassoo Jr. (Gemological Institute of America)

Описание: Diamonds have been mined in Guyana for more than 130 years and are traded in major diamond centers in Belgium, Israel, and United Arab Emirates. Notwithstanding this long history, the primary source rocks of Guyana’s diamonds remain mysterious. Most of the diamonds from the Guiana Shield are likely derived from unknown rocks of the Roraima Supergroup and may include primary igneous rocks. There have been a handful of scientific studies which address Guyana’s diamonds provenance and formation, but there has not been any of detail aimed at the exploration or gemological community. I present a description of Guyana’s diamonds to serve as a comparison with other diamond populations in the Guiana Shield and elsewhere. I include details concerning color, morphology, nitrogen content, luminescence and how we may use these observations to identify primary diamonds. Diamond inclusion composition was also measured insitu and used to inform us of the cratonic root beneath the Guiana Shield. I also provide an overview of diamond mining practices and production. Being Guyanese, I grew up hearing about Guyana’s diamonds deep in the Amazon jungle, which sparked my imagination and scientific curiosity. I combine my observations and historical accounts to provide an overview of diamonds and diamond mining in Guyana.