Mineral notes:

Current status of the boltwoodite workings near Goanikontes, Namibia

by Tomasz Praszkier

   During one of our trips through Namibia in 2025, we visited a famous location known for boltwoodite and other secondary uranium minerals - Goanikontes, situated about 30 km east of Swakopmund in the Erongo Region (⁦https://www.mindat.org/loc-7864.html⁩).

   The Goanikontes area is built mainly of Neoproterozoic age sedimentary rocks (Chuos Formation), intersected by spectacular dikes of black igneous rocks, which stand out beautifully against the host rocks, in a moon-like desert landscape.

   Secondary uranium minerals at Goanikontes occur in calcite pockets (some quite large), within carbonate (possibly dolomitic) lenses, hosted in the Neoproterozoic sedimentary rocks. Uranium minerals were first discovered here in the 1970s, and the site was briefly mined in a small open pit in the 1990s. During that operation numerous specimens containing spectacular yellow to orange radial sprays of acicular boltwoodite crystals were found. In most cases they occured on drusy calcite, and sometimes were partially coated by gypsum. Although most of the specimens extracted were relatively small, they set a new quality standard for species such as boltwoodite and weeksite.

   Today, the site has been abandoned and largely forgotten for several decades. Even after 30 years since the quarry was shut down, it is still possible to find boltwoodite specimens in the dumps. We managed to collect several pieces and plan to return to Goanikontes in the future with larger equipment to try our luck again!
 

Map of Namibia with marked location of the Goanikontes area.

Map of the Swakopmund area with marked location of the Goanikontes.

Drone view to spectacular geology of the Goanikontes area – black dikes of igneous rocks intersecting Neoproterozoic sedimentary rocks. Spirifer Minerals photo.

Desertous landscape in  the Goanikontes area. Spirifer Minerals photo.

Desertuous landscape in  the Goanikontes area. Spirifer Minerals photo.

Drone photo of the desertuous area near Goanikontes with marked boltwoodite workings. Spirifer Minerals photo.

Drone photo of the desertuous area near Goanikontes with well visible old boltwoodite workings. Spirifer Minerals photo.

Desertuous area near Goanikontes with abandoned boltwoodite workings. Spirifer Minerals photo.

View to the old boltwoodite workings. Spirifer Minerals photo.

Patryk from Spirifer team collecting boltwoodite specimens. Spirifer Minerals photo.

Big calcite pocket – some of them contained spectacular boltwoodite aggregates. Spirifer Minerals photo.

Freshly collected boltwoodite specimen. Spirifer Minerals photo.

Freshly collected boltwoodite specimen. Spirifer Minerals photo.

Freshly collected boltwoodite specimen. Spirifer Minerals photo.

Old classic boltwoodite specimen from Goanikontes, collected probably in 1990s. Specimen size 6.2 cm. The Arkenstone specimen and photo.

Relatively large boltwoodite aggregate (diameter 2.2 cm) on calcite, with gypsum. Collected in 1990s. Spirifer Minerals photo.

Relatively large boltwoodite aggregate (diameter 2.2 cm) on calcite, with gypsum. Collected in 1990s. Spirifer Minerals video.