Pyrrhotite (rare locality specimen)

Item Description

According to the entry on mindat.org, Morro Velho is, "The world's oldest continually producing gold mine, started in 1725". Although this locality is primarily a gold mine, it has produced some beautiful and singular examples of multiple species. Pyrrhotite is not necessarily rare from this locality, but most of the crystals you'll find are either micros or fairly crude larger examples. This piece dates back about 50 years (early to mid 1970s) and is a fine quality group of sharp (especially for the size), well-formed, pseudo-hexagonal metallic dark bronze crystals, free of matrix. Pyrrhotite is iron sulfide, and consequently it can oxidize, creating a light orange-golden hue on the surface, which is exactly the case with this piece. It gives the specimens an antique patina appearance, and really gives it character. When you see a Pyrrhotite these days, you pretty much assume it is from Russia, China or Mexico, but to find a robust example from this classic Brazilian locality is rare.