Cuprosklodowskite
- Jachymovit
The mineral cuprosklodowskite ( in older sources also Jachymovit ) is a rarely occurring uranium mineral with the chemical composition of Cu [ (UO2 ) 2 ( SiO3OH ) 2] • 6H2O. It crystallizes in the triclinic crystal system and usually develops needle-shaped, radial- grass-green crystals.
Special Features
The mineral is classified as highly radioactive due to its uranium content of up to about 55 % and has a specific activity of more than 98.9 kBq / g (compared to natural potassium 31 Bq / g).
Etymology and history
Cuprosklodowskite was the first time in 1933 (then Belgian Congo ) and 1935 of them described by Vaes on a mineral sample from Katanga independent of Novacek on a sample of Jáchymov ( Jachymov ), who named it after the place where Jachymovit. The identity of the two mineral samples was detected shortly thereafter by Novacek (1935 ) and Billet (1936). The name of the mineral is due to the erroneous assumption that it is this mineral is the copper analogue of Sklodowskit, which was named in honor of Marie Sklodowska - Curie.
The type of mineral is located at the University of Liege in Belgium.
The older name Jachymovit should not be confused with the recognized since 1996, basic uranyl Jáchymovit.
Classification
The dated 8th edition of Strunz lists the cuprosklodowskite in the " Uranophangruppe " with the system no. VIII/B.34 and the other members Boltwoodite, Kasolit, Natroboltwoodit, Oursinit, Sklodowskit, uranophane and uranophane - beta.
The 9th, completely revised edition of Strunz lists the cuprosklodowskite in the Department K " uranyl island and layer silicates with a uranium: silicon ratio of U: Si = 2: 1" in the group 9.AK.10. This group includes further Oursinit and Sklodowskit.
The commonly used in English-speaking classification of minerals according to Dana assigns the cuprosklodowskite in the Uranophangruppe the Department of island silicates, there, however, in the department of " island silicates with SiO4 groups and other anions and complex cations with ( UO2) " with the system no. 53.03.01.04 one.
Education and Locations
Cuprosklodowskite occurs in the weathered zone of primary uranium ores and was in addition to the localities in Katanga (Democratic Republic of Congo) and Jáchymov (Czech Republic) among others in Lodève (France), on Athabaskasee (Canada ) as well as in Utah and New Mexico ( USA) found.
Crystal structure
Cuprosklodowskite crystallizes in the triclinic space group P 1 ( Raumgruppen-Nr. 2) with the lattice parameters a = 7.052 Å; b = 9.267 Å; c = 6.655 Å with α = 109.23 ° β = 89.84 ° and γ = 110.01 ° and one formula unit per unit cell.
The basic structure of Cuprosklodowskits consists of a chain-like layers of edge-sharing pentagonal bipyramidal Uranyleinheiten whose equatorial oxygen atoms are each connected by tetrahedrally coordinated silicon atoms. The silicon atoms coordinate between three Uranyleinheiten; the fourth binding site is thereby satisfied by a hydroxide ion. The Cu2 ion connects two adjacent layers by bridging two oxygen atoms of opposing uranyl units.
Precautions
When dealing with cuprosklodowskite is to ensure adequate radiation protection. To prevent incorporation ( uptake into the body ), is thorough hand washing after handling with bare hands is recommended.