This is a chunk of Michigan clay with sand and probably calcium. I do not know yet if I can do much with it other than perhaps cut down the size to have the fossils. Don't know if a hack saw would help much. all are like micro size and one looks like an Crinoid Archimedes screw 0.7 cm x 0.3 cm. I would like to know what is the tire track like tract line? 5/8th inch, or 0.1 x 1.59 cm or 15.8750 mm. Is this an actual fossil or impression left by a life form. Two are with my phone zoomed in about 1.7.