Mineral: Thorite
Locality: Ambatofotsy pegmatite, Mahavelona, Soavinandriana District, Itasy Region, Madagascar
Dimensions: 7.5 x 5 x 6.5 cm

Description: Mass: 339 g MIM number:1880 Grayish crystal, altered by the radioactivity of thorium, showing nevertheless some faces typical of the quadratic symmetry of thorite, isomorphous to zircon. This crystal is considered very large for the species. Because thorite is highly radioactive, specimens such as this one are often metamict: This is a condition found in radioactive minerals that results from the destructive effects of its own radiation on its crystal lattice. The effect can destroy a crystal lattice completely while leaving the outward appearance unchanged. Photographer: AINU / Augustin de Valence Ex collection Jean Béhier (France)

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