…. but be very careful with fragile fossils (like bigger mammal teeth) … the H2O2 is also able to destabilize and to open existing cracks that are naturally cemented. You should at least make some images of the fossils before H2O2 treatment. If bigger fossils break you may better be able to rearrange the fragments. It works best with very fine sediments like silt and clay, especially with marin sediments or swamp sediments.