Boltwoodite - Encyclopedia
Class : Silicates
Subclass : Nesosilicates
Crystal System : Monoclinic
Chemistry : (H3O)K(UO2)SiO4
Rarity : Rare
Boltwoodite is a complex uranium-potassium silicate, one of many secondary uranium minerals that form by surface weathering of pitchblende and uraninite. It was named in honor of Bertram Borden Boltwood, a radiochemist at Yale University and a pioneer in rock dating using the U/Pb method. Boltwoodite crystals are acicular or fibrous, small (less than 1 cm), and usually occur in radiating yellow aggregates. It is a highly radioactive mineral (over 66% UO3).
Main photo : Boltwoodite from Goanikontes, Erongo, Namibia © Elise Chaigneau
Boltwoodite in the World
Twinning and special crystallizations
No twin known for this mineral species.
Fakes and treatments
No fake identify for this mineral species.
Hardness : 3.5 to 4
Density : 4.7
Fracture : Irregular
Trace : Yellow
TP : Translucent
RI : 1.668 to 1.703
Birefringence : 0.007 to 0.008
Optical character : Biaxial +
Pleochroism : Low
Fluorescence : Green
Solubility : -
Magnetism : None
Radioactivity : Very strong