Why “hexagonal dipyramidal”? Well, why not?
In all seriousness, hexagonal dipyramidal (6/m, or C6h in crystal notation) refers to a particular crystal system in mineralogy, and is the form taken by my favourite mineral, which you may have also noticed in the background – pyromorphite. The vanadate analogue of pyromorphite, vanadinite, also occurs in this system, as does the arsenate analogue, mimetite. A more detailed discussion of these three minerals is in the works, and will be linked here soon.
The block image block at the top of the page is a warped version of the first American issued mineral stamps, which were oriented in a diamond pattern, and originally issued in 1974 (for more about minerals appearing on stamps, try Mineral Stamps, a website on which many images of minerals appearing on stamps from around the world are archived. This is the unaltered version:
Minerals made a second appearance on US stamps in the 1990s with this series, bringing the images somewhat up to date but, I think, lacking the more traditional (and cooler) traditional “stamp-like” engraving graphic:
Stamps appear on minerals throughout the world, and happen to coincide with another of my areas of interest. In the near future, there will be a post about that as well.
In the meantime, thanks for reading, and be sure to leave a comment or drop me a line if you have questions!