Black Pearl
	The jewel was created by Hosenki, a demon oyster who made the pearl for Inuyasha's father.
	It resembles a normal pearl that is black in color.
	The Black Pearl is hidden behind Inuyasha's eye and contains the portal that leads to his father's tomb in the netherworld. A long time later it is discovered that the final Shikon fragment also lies in the netherworld, but the demon who forged the Black Pearl has sinced passed away, and his successor is not capable enough to forge a new one.
	When Sesshomaru learns that the pearl is hidden behind Inuyasha's eye, he tears out his brother's eye and uses the pearl to travel to his father's grave in an attempt to gain the Tessaiga for himself. Ultimately the pearl's discovery leads to Inuyasha claiming the sword as his birthright.