I think maybe a better approach I saw was to sweep and vacuum up NY City sidewalks for gemstones that have fallen out of people's jewelry. It's similar to the

I think maybe a better approach I saw was to sweep and vacuum up NY City sidewalks for gemstones that have fallen out of people's jewelry. It's similar to the idea of sweeping up the edges of high travelled roads looking for palladium. But I think the palladium recovered wasn't worth the effort. But the gem stones might be, even if they're tiny.