Thread: What actually is Hardness in natural stones, and how it affects sharpening

Originally Posted by Lesslemming

Maybe, but there are many exceptions to that rule. Not only is "hardness of a stone" still undefined,
but what I would call a very hard synthetic stone (the shaptons, 16000 or 30000 for example, or the pro 12000) may be extremely quick
at removing scratch patterns and cutting microbevels etc. The Shapton 16.000 is staggeringly quick and can (not should) be used after the Cerax 6.000 with a couple of circles.

Yes, but the Shaptons are synthetic stones. They are still quick,despite being
hard, because they are loaded with grit particles. If a fine and hard stone is very
quick that either means the particles are very hard(think diamond)or the stone
has a lot of sharpening particles per square unit or both. Might be wrong though.

Sharpman