Kor
this is the rarest, and purest, form of ryll spice produced on Ryloth. It makes up only three percent of the total ryll production, and virtually none of it leaves the planet. It was discovered that kor ryll had certain medicinal properties. This was found by Qlaern Hirf and his Vratix verachan, who were working to counteract the effects of the Krytos virus. The New Republic sent Rogue Squadron, with Nawara Ven, to Ryloth, in hopes that they could negotiate a supply of kor for use in augmenting bacta. Kor ryll absorbs light in the ultraviolet range, and appears black under normal lighting. It can be distinguished from colored, less pure ryll under ultraviolet lighting. Petrified forms of kor, useless as a source of spice, were often carved into various shapes and sold as works of art.