greywacke

Noun

Meaning

greywacke (countable and uncountable, plural greywackes)

(geology) A hard dark sandstone with poorly sorted angular grains of quartz, feldspar, and small rock fragments in a compact, clay-fine matrix.

Source: en.wiktionary.org

Close letter words and terms

Greystones Greytak Greytown greyware greywater greywether