Five sided crystal faces
In my last blog post, I mentioned how a crystal with regular five-sided crystal faces caught my attention. In a comment on the blog, the word “pyritohedrons” was mentioned. Most pyrite crystals are cubes. This picture is a pyrite that is on display on the second floor of the Museum of Natural Sciences, showing the five-sided crystal faces. This sample comes from a pyrophyllite mine in Moore County, North Carolina, and it is unusual enough to be, well, in a museum. When I got my new camera, this is one of the first shots I took.
If you look closely (hint: click on the picture), you can see how the pentagonal faces of the pyrite crystal are somewhat distorted, not quite a true pentagon. The quasicrystals showed faces that did not look distorted, hence my fascination.