So been fiddling with fake stones, if interested here are the settings for these pesky lil critters:-)
Seed 48811
Scale/Density
*stone scale 12
Stone Density 0.7
"vary density checked" 1
Density seed 41275
Density variation scale 10
SHAPE
Stone tallness 0.66875
Pancake Effect 1.85
only displace upwards checked
Everything else is default settings
I added this displacement function to a surface shader as a child layer that way you can control the altitudes slopes etc as to where you can place the stones, then in the stones you can add the color, image map or whatever. Hope this helps anyone out.
Thx. It can be a good jump-start for an image.