Boltwoodite
1 in the gallery
Boltwoodite is a uranyl silicate mineral that forms as hydrous, yellow to brownish crystals, often with slender, needle-like or radiating habits. Its lustre ranges from silky to resinous, and it typically occurs as micaceous or clumped aggregates in secondary uranium-bearing environments. The mineral’s characteristic composition includes uranyl groups coordinated with silicon-oxygen tetrahedra and water, reflecting its hydration state and complex crystal chemistry.
- Formula
- (K,Na)(UO2)(SiO3OH) · 1.5H2O
- Rarity
- Rare
- Stability
- Unstable
- Collector interest
- High Interest
Where Boltwoodite is found
Top localities
- Arandis1 specimen
About Boltwoodite
Notable specimens come from Namibia, where secondary uranium deposits provide the oxidized, weathered zones favored by boltwoodite formation. In these settings, boltwoodite often fills crevices and intergrowths with other secondary uranyl minerals, yielding specimens with a warm, earthy tone and a delicate, glassy surface that can catch light in interesting ways. Collectors prize its fine-grained textures and the rarity of pristine crystals, which convey the mineral’s fragile hydration and interpretation of secondary alteration processes in uranium-rich environments.