This 7 cm long rock was collected on the sandy flat near Sponge Cliffs. It is loosely cemented biogenic material, such as shells and hard part remains of organisms. It is not one of the rocks that makes up the foundation of the cliffs and terraces of the region.

Collected on JSLII Dive 3460, sand flats near Sponge Cliff, Blake Plateau (1995 ft).