Renewable Sand and Gravel via Amethyst Golems

An amethyst golem can be created by placing a carved pumpkin on a *budding* amethyst. These golems will pick up dropped cobblestone and "chew" it into gravel. Likewise they will pick up gravel and "chew" it into sand. Thus sand and gravel will become renewable, so we no longer have to destroy our deserts. 

I think it would be very cute if the eating animation took inspiration from the way otters crack open sea urchins. The golem would lie on its back and crack the block against its belly.

As for the appearance of this mob, I'm imagining something like the crystal monsters from the "Power miners" lego theme, but it would be nice if they took inspiration from the layers of a geode.

Inevitable, players will trap these golems in pods, like they do with Piglins and Villagers, so I'd like to see a mechanic introduce to prevent this. Perhaps golems will refuse to eat unless they can stop for "enrichment". Perhaps they just need to run in circles for a little while or make "music" by hitting amethyst crystals. Hopefully this could pave the way for similar mechanics for the ethical treatment of Piglins and Villagers.