Dramatic, bright yellow-orange, acicular, radial sprays of the rare uranium silicate mineral boltwoodite are perched on dark grey-brown calcite matrix on this wonderful thumbnail specimen from the Goanikontes Claim in Namibia, which is widely believed to be the source of the greatest finds of the species to date. From the well-known Namibian mineral collection of Shields and Frances Flynn, who self-published the book, Minerals of Namibia - From the Collection of Shields and Frances Flynn in 2018.