BB pal Paul Boutin points us Elemental Hexagons, a tarot deck which incorporates the periodic table of elements. Divination and chemistry, together at last! Snip from explanation by the deck's designer, Calyxa, who came up with the idea while studying Earth Sciences at UC Santa Cruz:
One day in one of my Mineralogy classes, a class devoted to understanding how various chemical elements combine to form rocks and minerals, I was looking at the periodic table on the wall. In my spare time, I had been studying the occult and the Tarot, and I'd learned about how the Major Arcana represented the fool's journey through life. The progression from one element to the next in the periodic table reminded me of the fool's journey and that was the seed of the idea.
One big problem with trying to make a deck out of the periodic table is that the table is open ended. New elements were being discovered left and right. So my first hurdle involved making some hard decisions about which elements to include. I decided I'd use 36 elements. I'd use the first 18 elements of the table, and then 18 others which for one reason or another called out to be included. Many of those were elements with historical significance, such as Gold and Iron. Others were included for numeralogical reasons, for example, Vanadium, which is atomic number 23.
As I selected elements, they sorted themselves into groups. I ended up dividing the deck into four suits, each with three sub-groups of three elements each.