Thanks for the info Steve.
The hard particles were distributed evenly throughout the drywall like aggregate in concrete.
Other than fire retardancy, I cannot think of a reason a manufacturer would put these particles in the drywall. That's why I'm thinking it may have been asbestos.
I was wearing a mask but even so I think I took in a fair amount of dust. It was one of those cheap paper jobbers.
© 2017 Renovate Your World LLC