This blastoid takes on a blackish appearance in its photos. Identified as a
Pentremites from the Glen Dean Formation of Grayson County, Kentucky. It is dated to the Mississippian Period.
This area is also known for color banded blastoids. See this link for one:
https://twitter.com/Clarkeocrinus/status/478722583790370816/photo/1
https://twitter.com/Clarkeocrinus/status/365284115316088834/photo/1