These highly compressible sponge rocks and boulders are great production items. They look like real, heavy, chunks of gray granite rock. In reality however, they are hand crafted from foam rubber.
 
Feeling a little boulder? Got a rock in your shoe? Remove your shoe and pull out the giant sized rock!
This next trick, I take for granted (granite). Produce a rock!
I had to leave the granite industry. It was counter productive!
They wanted to add Chuck Norris' face to Mount Rushmore, but the granite is not hard enough for his beard!
It takes a boulder person to read through this list of puns.
 
Ok, ok, just buy one and we will stop. Each “rock” is a different configuration, but each measures about five to six inches in circumference. Goshman went out of business and these are no longer made. We only have a few left in stock. 001CBMSPONGEROCK