I've got several!

Diamond - a beautiful, sturdy gem formed under extreme conditions; it's also used to promote courage, passion, and positivity
Celestite - brings light and love into the home when on display, and Lee is very open with his affections
Blue kyanite - linked with past lives, time travel, compassion, and telepathy, which I link to the otherworldly and spiritual aspects of his development
Moonstone - a boost to magic and mysticism, which is a nod to his mastery in sorcery
Galaxite - aside from the obvious cosmic motif, galaxite balances energies and promotes healing/cleansing
Corundum - a mineral that forms into rubies and sapphires, encompasses passion, wisdom, strength, love, and devotion, among other things; also a nod to his GNB (Heart of Corundum)

The meanings are derived from "The Crystal Witch" by Shawn Robbins and Leanna Greenaway. It's my go-to book for crystals and stones.