graywacke

English

Noun

graywacke (countable and uncountable, plural graywackes)

1. Alternative form of greywacke
   • 2007 December 12, Anthony Depalma, “An Island in the Hudson, Plundered in Search of Indian Artifacts”, in New York Times‎^[1]:

     Hundreds of projectile points and ceramic pieces from the island are stored in the State Museum in Albany, and archaeologists found human bones at a burial site from the early Woodland period at the back of the rock shelter, a 45-foot-long overhang of graywacke, a local sandstone.