Earlier quoted context omitted.
Sounds like crummy chalk -- a good blackboard with some chalk is heaven for me. Whiteboards are so sterile. https://www.youtube.com/watch?v=PhNUjg9X4g8
I will never miss whacking the erasers to remove the chalk dust in the morning as a child or the screech of chalk.
The “dust” from a whiteboard is worse, imo. And I used to like clapping the erasers!