Acanthite

Item Description

This a beautiful thumbnail specimen from Imiter. This a few rather sharp, dark, grey, well-formed pseudo-octahedral crystals of Acanthite forming a showy overall specimen. It's very three-dimensional and is virtually undamaged. It's important to note that some people label these specimens (and Acanthite in general) as being pseudomorphs after Argentite, but they are technically paramorphs as Acanthite will actually transform into Argentite in an environment where the temperature reaches above 177° Celsius, but they are not pseudomorphs. A wonderful piece of this classic and now rarely seen material.
From the collection of Vasco Trancoso, a medical doctor and prominent mineral collector from near Lisbon, Portugal (https://www.mindat.org/user-11954.html). He assembled his mineral collection over the course of 60 years, and built a fine worldwide display collection that we recently purchased. This piece is pictured on mindat.org at https://www.mindat.org/photo-187041.html