If you’re reading Hackaday, there’s a good chance you had a rock tumbler in your younger days. Hell, we’d put odds on a few of you having one rumbling away in the background as you read this.

Ah yes, the ol’ National Geographic-branded rock tumbler. “Polish everyday rocks into dazzling gemstones!” promises the $59 product on Amazon aimed at avid geology enthusiasts.

Steve Jobs believed that friction and debate among talented individuals lead to innovation, comparing it to rocks polished in ...