This is a dagger carved from obsidian, used in pagan times by a cult of witches to cut the hearts from their wretched victims. The secrets of performing this dark ritual have been lost, but dedicated research might reveal them. If the ritual is performed properly on the correct evening, six pawns of Corpus vis can be gathered from the heart of the victim. This vis may well be tainted with the Infernal, and is certainly ill-aspected, being the wicked gains of the act of murder.