Gifted to Kili by his mother, this labradorite stone bore six runes etched onto its polished surface: Return to me. A constant reminder of a promise he made before their quest began.

It is a talisman, a powerful spell lies upon it. If any but a dwarf reads the runes on the stone, they will be forever cursed, or not. Depending on whether you believe that kind of thing. It's just a token - a rune-stone. My mother gave it to me so I'd remember my promise.