Locality: Assunção Mine, Aldeia Nova, Ferreira de Aves, Sátão, Viseu, Portugal
Dimensions: 6.5 x 4.5 x 4.5 cm.
The Assunção Mine, a large beryl-bearing granitic pegmatite mine in northern Portugal, became well-known to collectors around the world, especially collectors of secondary uranium minerals, after a spectacular find of world-class crystallized autunite was made around 2005/2006. Autunite specimens from the Assunção Mine feature large (up to several cm) very well-formed, electric-green crystals, sometimes on a matrix of smoky quartz, in exceptional plates up to nearly 20 cm. across. Destined to be future classics for the species, these fine autunite specimens were quickly swallowed up by collectors and museums, and now have become scarce on the market. This fine example features well-formed, undamaged, bright green autunite crystals to 1 cm filling a vug on minor matrix. A fine example of this beautiful and sought-after rare species. Annette Slade photo.