Rocks

Model

A geosphere with this:

The noise ... vary this and other settings to differentiate each rock ...

Taper and Squeeze are only to continue to misshape the stone ... so don’t get hung up on these settings:

Meshsmooth:

The UVW map ... anything that avoids streaking ... I used BOX:

Map

Here is your bitmap, although you can use something of your own ... Max has this one:

Play with the same map in bump, specular level, etc:

If you use specular level, remember to intensify that color; i used a light yellow:

Finally, arrange your rocks; rotate them, scale them, change the noise seed and the other modifier settings to get variety.