Periapt Shard
From Tomb Raider Wiki
Periarpt Shards are ancient weapons of the Lux Veritatis. Three of them were entrusted to the Lux Veritatis leader, Konstantin. Konstantin passed the shards down to his son Kurtis Trent. Eckhardt tried to stop the passing of the weapons as they are the only thing that can kill him.
Eckhardt murdered Konstantin, but failed to stop the shards from being passed down.
