[amluto]

This is an oversimplification. Quartz doesn’t break down either, and yet people don’t worry about bioaccumulating sand when they go to the beach.

[red-iron-pine]

you don't absorb quartz through your skin and is inert if it gets into your stomach. small particles won't hurt your guts and will get pooped out; ingesting dirt is something that is not uncommon with animals, including people.