Chalcostibite Altering to Azurite

Item Description

A rare and showy pseudomorph replacement of lustrous, striated, saturated colored azure-blue azurite after a large chalcostibite crystal nicely set in matrix from a MOST UNCOMMON locality - Rar-el-Anz, Morocco. Chalcostibite is an uncommon sulfosalt. This pseudo is REALLY GOOD and is nicely terminated. Seldom available on the market in quality, and yet on matrix as well! All of them I have ever seen, come from this locality. The replacement of the azurite is skin-deep, with a remaining chalcostibite core you can see from below, and by heft... Specimens like this are few and far between, and I have been told many date to the early to mid 1900s, and the French expeditionary service collecting trips here. Certainly, I have not seen any recently. This piece came from an old collection.