Associations to the word «Greywacke»

Wiktionary

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

Wise words

The chief virtue that language can have is clearness, and nothing detracts from it so much as the use of unfamiliar words.
Hippocrates