She took some more of the gray stuff back to the lab with her, to do more extensive testing.

The gray stuff you were eating off the rock.

The gray stuff behind them is sand and dirt.

The floor was of the same gray stuff as the walls.

"That's what the lump of gray stuff is on his plate."

Tach asked as he began to scrape up a few flakes of the gray stuff.

Actually, the gray stuff had spread a lot further than the last time he looked.

Even her feet were shod with high buskins of this grey stuff.

Inside there curled a thick sheet of the same softly resistant gray stuff.

The entire view from her windows was shut off by the spectral gray stuff.