Usage examples for Wacke:

• A beautiful bust of gray- wacke in our possession probably represents the same king. "The Complete Historical Romances of Georg Ebers" – Georg Ebers

• The newest of these, connected with the higher series of coal- measures, is well exhibited along the shores of the Forth, in Fifeshire, where they consist of basalt with olivine, amygdaloid, greenstone, wacke and tuff. "The Student's Elements of Geology" – Sir Charles Lyell