Contrasting nicely with its white calcite matrix, is a cluster of isometric, silver colored, skutterudite crystals, to 1.2 cm in length, which exhibit good metallic luster. This is an exceptional, well crystallized skutterudite from a rare locale, self-collected by a Spanish customer/collector whose collection we bought last year. I have not seen comparable on the USA market, at least. Relatively aesthetic, as the crystals are contrasted to nice white calcite matrix from which they are partially excavated.