He went to the gray rock and pointed, looking down at me in the yard.

It is summer and these grey rocks have turned to a fresh pale green.

I took my place at the side of the grey rock.

The gray rock rose up in front of me.

He stepped out into the open, balanced on the gray rock.

It was a dead gray rock, devoid of even an atmosphere.

Suddenly Frank stopped and pointed to a dark opening in the gray rock ahead.

The voice was coming from under one of the gray rocks.

Did they have to make their city out of grey rock as well?

A staircase cut from the natural gray rock curved down to the level below.