With the lower hills, the packed dark clay of the road had turned drier, redder, and dustier.

The sub-soil is dark packed clay, with a high iron content.

The forewings vary from dark clay coloured to light yellowish brown.

The Americans will need to be focused to prosper on the dark red clay the Russians carefully chose as a surface.

The rammed earth was then coated with dark brown (nearly black) clay.

Black and dark grey clays indicate a moderate or high organic carbon content.

The soil of the surrounding area is a heavy, dark clay; this indicates that the area was routinely flooded.

It was human in look, though as hairless and smooth as if sculpted from dark clay.

Soil as having very dark brown clay, blocky, hard and quartz throughout the layer.

All are made of a dark orange-red clay.