Warring Kingdoms of Mysmall
Notched along it’s edges and etched through with dwarven runes. While these alterations to any other gem would be detrimental it seems that there is a power stored in this gems core that keeps it solid.
Resting in the shallow hilt of a dagger and acting as it’s blade the rough notches in the diamond act like a serrated edge as the energy of the stubby blade helps etch it’s victim with a pure jolt of pain.
It appears to be located in a deep crevasse, surrounded by the bones of many a dead dwarf, and other more fresh carcasses.