vat is tba?
Stones should have a "hard" ability, nice and straightforward. Gems should have a "soft" ability or an ability that can be used in many ways. Stones are more likely to be used in monos while gems would more likely be used in duos, trios, quartets, or rainbows.
A hard ability would be "Ablaze". It would be used just for fire, or random mutations,
A soft ability would be "Mitosis". It would be used for any creatures, such as sparks or forest spirits or good creatures.