Quiruvilca is famous for many things in mineral world, and it is known as one of the world’s great localities for octahedral crystals of pyrite. This is one of two very similar specimens I acquired in Peru that show perfect crystals that combine both octahedral and pyritohedral faces (the other is #100251). This is textbook! The crystal faces have varying lustres – they are mirror-bright (and tough to convey in a photograph where you’re trying to highlight the crystal habit – but the lustre is the same on all of the crystals). There are some etching patterns on some crystal faces which give mottled, and, in these places, silkier lustre from certain angles (if you can picture silky and metallic together).  In person it looks like a typical bright Peruvian pyrite – the photographs over-emphasize the etching. Of the two specimens, this one has a bit more of the etching.

This is a mound of crystals that can be viewed from any angle. It is in excellent condition – a couple of tiny nicks and a bit of damage down close to the base where it was removed from the matrix – none of this is distracting, and this is certainly an extremely high quality specimen as Peruvian pyrite goes. The largest crystal is 2.0 x 1.7 cm. This piece is most important for the awesome combination crystal forms of octahedron and pyritohedron.

If you’d like to see photographs of Quiruvilca, including underground in the mine, see Into the Andes: Quiruvilca, Peru .