Last week, Gary Ross Dahl, the genius behind the “pet rock” died. Though the rock enjoyed a relatively short time in the sun, it’s hard to find a baby boomer that hasn’t chuckled at least once at the absurdity of stone companion.

Prior to inventing the “Rock,” Dahl was an executive for an advertising agency. One day in 1975, while writing an instruction manual, Dahl was struck with brilliant idea: put a rock in a box, then write a tongue-in-cheek manual telling owners how to take care of their rock. The idea was a hit. Three months after the rock was released, over one-million people shelled-out nearly $4 each for a pet rock.

Dave Leavy is the owner of Big Kid Collectable Toy Mall. He says there’s no substitute for the pet rock experience.

“Well, it’s really the box,” says the toy man. “It’s really the packaging. The idea of having the leash in there for it, the instruction book … it’s very funny.”

Leavy sells pet rocks at his store in Sherman Oaks, but he says demand isn’t anything like it was 40 years ago.

“I can’t say they’re necessarily a huge seller. We probably sell two or three of them a week, but everyone talks about them. Everyone shows their children.”

Leavy says baby boomers still get a kick out of seeing the pet rock on his shelves, but they’re rarely willing to buy one; they sell for about $9 each.