Rune

The Nida place runes in stones and gems to imbue them with magic.
The runes usually need to be activated, but this is not a requirement.
A fire rune set on a stone box to protect it could burn an potential thief or on a door would deter trespassers. However they are not only destructive; in the case of Hot Stones, the fire runes are used to heat the stone to cooking temperature.
Using a rune will expend all of the magic within it and in doing so will wipe the rune from the surface of the stone/gem.