Editing Torbernite (section)

== Properties ==
[[Image:Torbernite - Kerguillo quarry, Bohars, Brest, Finistere, Brittany, France.jpg|thumb|left|A pyramidal torbernite crystal from Brest, France<br>(Field of view: 7&nbsp;mm × 5&nbsp;mm)]]
[[Image:Metatorbernite - Les Montmins Mine, Echassieres, Ebreuil, Allier, Auvergne, France.jpg|thumb|Intergrowth of dipyramidal crystals of metatorbernite in a geode from Les Montmins Mine (Ste Barbe Ader), Échassières, Kanton Ébreuil, Département Allier, Auvergne, France (Field of view: 1&nbsp;mm × 1&nbsp;mm)]]

=== Morphology ===
The mineral is often encountered as small thin tabular crystals, but may also be flaky or powdery. More rare are thicker plates, resembling a stacked deck of cards. More frequent than these are dipyramidal forms.

=== Physical and chemical properties ===
Because of its uranium content of about 48% the material is strongly [[Radioactive decay|radioactive]]. According to the sum formula a specific activity of 85.9&nbsp;k[[Becquerel|Bq]]/g<ref name="Webmineral" /> can be given (for comparison: natural [[potassium]]: 0.0312&nbsp;kBq/g).

Contrary to its calcium analogue autunite the mineral does not fluoresce.<ref name="Klockmann" /> 
The mineral is very brittle. Its hardness (Mohs) is between 2 and 2.5.