Based my gemsona off the cards connected to my sun/moon signs (Libra/Scorpio), Justice and Death cards in the RW tarot. That being said, I chose chiastolite due to its meta physical properties:

Chiastolite is a stone of balance and harmony. It can help with mental / emotional balance, stability, enhancing problem solving, adapting to change, memory, and ability to see all sides of a problem. Chiastolite can enhance spiritual awareness and harmony, as well as practical creativity. By practical creativity I mean being able to creatively think of new or different solutions to problems or issues. - http://meanings.crystalsandjewelry.com/chiastolite/

Justice has a sword, crown, and of course scales. Sword is the weapon, the crown is mimicked somewhat with the scarf, and I tried to incorporate balance to replace the scales (which meant a symmetrical design for me).

The only element of Death I could have used in this  design was the flower on its flag, and incorporated the star in with that. I was thinking of maybe fusions including caer would have more of Death than Justice in design, since one keyword for Death is 'transformation'.

I actually did make a design for Death, however it was too cluttery so I scrapped it.

Hmu if you wanna fuse B)