About

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.

Other Notes

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:

U.S. Mineral Stamps, 1974

The first series of US stamps to feature depictions of minerals. Shown, clockwise from upper left, are amethyst, petrified wood, tourmaline, and rhodochrosite.

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:

 

US Mineral Stamps, September, 1992

The second series of American mineral stamps, issued in September, 1992. These stamps feature (clockwise from upper left) variscite, wulfenite, native copper, and azurite.

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!

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