Mineral description : Boltwoodite

Mineral class Silicates : Nesosilicates : Uranophane group
Chemical formula K2H2(UO2/SiO4)2.4H2O
Crystal system Monoclinic.
Habitus Massive as crusts or as acicular crystals.
Hardness 3.5-4
Density 3.6-4.3 depending of water contents.
Color Yellow to pale yellowish, crystals transparent to translucent.
Streak Pale yellow.
Luster Vitreous to silky.
Description A rare secondary uranium mineral.
Occurance Often as thin crusts and surfaces on other rocks and in fractures.
Associates Uranite, other uranium minerals.
Notes Fluorescent.
Strongly radioactive.
Type locality : Pick's Delta mine, San Rafael Swell, Emery Co., Utah, USA
Locations A rare mineral
  • Västervik, in fractures or as surfaces on other rocks.
  • Lilljuthatten, Krokom, Jämtland.
  • Olden power plant, Krokom, Jämtland.
Notable occurances outside Scandinavia
  • Rossing Mine, Swakopmund District, Namibia.
  • New Method Mine, San Bernardino County, California, USA.
  • Arandis, southwest Africa.

To silicate index.
Mineral group index.
Main index.

If you have some questions, suggestions or comments you are welcome to write me a line or two.

To my homepage.
Last changed : 1999-01-01