I own three flowerpots with strange white inserts. I haven't bought them in fact they were already part of the 1970 built house when I moved in. I've heard of asbestos flowerpots but couldn't find anything about inserts. The material is greyish white and relatively easy to break.
Is it possible that these flowerpots are made out of asbestos?
(I wore a facemask, gloves and a face shield while taking the last picture)