Two groups of stacked acanthite crystals (pseudomorphs after argentite) intergrown with one another. This specimen features some good-sized acanthite crystals, the largest being 2.0 cm across. With magnification silver is visible, in small wires – some may be partly replaced by a second generation of acanthite. A distinctive acanthite.
About These Acanthites
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.