I am new to fossil preparation, I really want to prepare this echinoid I found on Jebel Hafeet, Al Ain, UAE.
I have started prepping it with a small needle, since I don't have access to any fancy machines, but I think I just ended up damaging the fossil. The rock seems to be a type of clay, not too hard. It might also be limestone, since the area is known for its shallow marine sedimentary rocks. Should I soak it in water? Or vinegar? Should I have a go at it with my dremel?