What grit are red blood cells?
So given that red blood cells are 1000th of a mm
there are about 4-6 million cells for 1 microliter of blood given that there's probably a teaspoon of blood on the stone. Provided it has an even coverage.
so given an average stone size of 3x8 we have 24 square inches.
a teaspoon of blood over the whole stone 15ml = 15000 microlitres
15,000 x 4 million = 60,000,000,000/24 = 2,500,000,000 per square inch
and that's just cells, which would break down quickly under the stone. So to answer your question steve 2,500,000,000 grit
This is all going with the assumption grit for stones is calculated the same way as sandpaper.
Yes, yes. I'm a smart ass.