The Gemmological Association of Great Britain (Gem-A) has launched the latest issue of its academic publication, The Journal of Gemmology (Volume 38, No. 7).
Released on 25 September 2023, this issue contains news and research from the international gemmological community, including an article dedicated to the historic 38.23 ct Banjarmasin diamond, which is in the collection of the Rijksmuseum in Amsterdam, the Netherlands. This diamond was cut from a 70+ ct octahedral crystal that was reportedly mined in southern Borneo. The rough material was confiscated by the Dutch from the Sultanate of Banjarmasin in 1860, and it was faceted in Amsterdam in 1870.
While past publications have focused mainly on the colonial history of the diamond, the authors of the present article (Suzanne van Leeuwen and J. C. Hanco Zwaan) have uncovered archival information about its faceting and efforts to sell it and have also documented the stone’s gemmological properties. As one of the few large diamonds from the alluvial deposits of Kalimantan, the results of this study contribute to the recognition of Borneo as an historically small but important diamond source.