Yes it is called sandcasting. Its used for a lot of different materials including iron and bronze. I don't know how much fidelity you would get from just pressing an object into sand, pulling it out, and casting. The sand needs to be packed very tightly. I haven't cast hypertufa but I usually take the form and make a wood frame that surrounds it. The form is placed flat on a flat surface with the frame around it and the wet sand is packed very tightly into the frame with a tamp. Than I screw on a back and flip the mold. Remove the form and your have a mold. That's the basics.

Thanks! I meant to post a please disregard this question because I found out shortly after I asked here.

Youtube had some really helpful ideas on sand casting, like using oiled sand.

There are a lot of tips to be had about sandcasting such aslay was traditionally used as a stabilizer for the sand.