A type of metamorphic rock characterized by its banded or foliated appearance, typically composed of alternating layers of different minerals such as quartz, feldspar, and mica.
The geologist examined the gneiss to determine the conditions under which it formed.
A sample or piece of gneiss rock.
Several gneisses were collected from the riverbed for laboratory analysis.
gneissadjective
Made of, containing, or relating to gneiss.
The trail wound its way along a steep gneiss cliff.