Because I'd like to see pretty crystal armor/weapons/tools, I'm suggesting this. Instead of mirroring Diamond equipment (Terrasteel does that), it'd be more along the lines of Gold: low protection/damage value (and almost no durability - having a mana source on you would be REQUIRED for these), but superior mining speed and enchantability, and the Armor set would provide a higher mana discount than Manasteel/Elementium (but possibly less than Terrasteel, at least for Mana Diamond - 15% would be just fine). May have special abilities, but that's not necessary.