TERRIUM — A mineralogy cabinet


Bassetita

Bassetita is a mineral with formula Ca(UO₂)₂(PO₄)₂·8H₂O, in the Fosfatos group. This specimen comes from Wheal Basset, Basset Mines, Carnkie, Carn Brea, Cornwall, Reino Unido and joined the Terrium collection in 1982.

Bassetita from Wheal Basset, Basset Mines, Carnkie, Carn Brea, Cornwall, Reino Unido — Terrium

Description

Orange-brown bassetite rosettes composed of multiple acicular crystals, some parallel, the majority radiating, on a dark matrix.

History of this specimen

Historic piece from the type locality, which was acquired in 1982 from the famous portuguese dealer Montal for 3,250 pesetas. It comes from the collection of Carlos Prieto Paramio and retains its original handwritten label.

About Bassetita

A scientific rarity—a dimorph of meta-autunite. A hydrated uranyl calcium phosphate that forms as a secondary mineral in the oxidised zones of uranium deposits. Uncommon and particularly significant when from its type locality.

About the locality

Wheal Basset, part of the Basset Mines group, is one of the classic Cornwall localities. The area produced numerous secondary uranium species, including bassetite, which was first described from material from this mine.

Technical data

Catalogue No.
0078
Composition
Ca(UO₂)₂(PO₄)₂·8H₂O
Name
Bassetita
Group
Fosfatos
Category
Núcleus Ardens
Matrix
Matriz oscura con costra irregular
Associations
Calcosina; posible uraninita
Mine
Wheal Basset, Basset Mines
District / Municipality
Carnkie
Province
Carn Brea
Region
Cornwall
Country
Reino Unido
Size (cm)
4 x 3.3 x 1
Weight
13.7 g
Acquired
1982
Ex-collection
Carlos Prieto Paramio
Etymology
Named after the Basset Mines group in Cornwall, England, where it was first described in 1915.
Quality
Notable
Value trend
Al alza

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