This is getting interesting. In about 30 mins I will use the most accurate and scientifically acceptable method to determine the grit of a stone. I'll try to lick them! I'm putting them in boiling water for 30 minutes, I'm a clean freak. All the stones are burnished from use to their finest degree, no sandpaper 600grit, lapping etc. Then I will post my results. If nobody is gonna do it, I will.