Conclusions
Stylolites develop a roughness because slower dissolving particles pin the interface. The stylolite pattern is a function of the size of the pinning particles (often the grain size), the amount of pinning particles and the pinning strength. The strongest influence comes from the size of pinning particles. This size dictates whether or not the stylolite starts to grow in the surface energy dominated regime (slow and fluctuating growth) or in the elastic energy dominated regime (fast growth that produces spikes and teeth). If the grain size is bimodal these different growth patterns and speed can overlap. The largest grain size will normally produce the dominating pattern.