Excellent thumnbnail-sized specimen of acanthite crystals (pseudopmorphs after argentite), with stacks at right angles to one another. Complete and well defined all-around. This one is striking – very architectural – aesthetic and distinctive!
Well-crystallized acanthite has never been common and most of the known localities for crystals are historic, making it difficult, and usually expensive, to obtain fine specimens. The finds at Imiter (Africa’s largest silver mine) in recent years have placed it among the world’s best localities for crystallized acanthite. Although these crystals formed as argentite, argentite is not stable below 179C, at which point it changes to monoclinic acanthite. The specimens are acanthite pseudomorphs after argentite, retaining the isometric crystal form of the original argentite crystals. I assembled this lot of acanthites over a period of about two years. Most of these specimens, from the 2008 find, remained in Morocco until 2013.