ToME: the Tales of Maj'Eyal

Some gems have very weird effects as bombs:
Jade (tier 4) - Additional 0 slow damage
I guess that's meant to slow enemies, but the description is pretty bad

Pearl (tier 5) - Additional 1 lite damage
No idea what that's supposed to mean. 1 damage at tier 5?

"Lite" damage lights up the tile. Basically it lets you use bombs to make the whole level glow.