Inflicted by the stone madness I too worked on some new stones. Biggest are 0.12 m, smallest 0.03. But a problem arises when you add a surface with displacement intersection (for the sand); the underside of the stones are 'smoothed into the sandy color'.
And a little tip that might be helpful, if you don't already know; if you add very small displacements (PF with 0.005 as smallest scale) the stones react weirdly and turn very dark (at least in my case), so I added very small fake stones, which works much better.
Nice! :)
Excellent !