Some before and after pictures of a Hemiaster whitei fossilized sea urchin. It is from Turrant County, Texas (Goodland Formation). The creature existed in the Cretaceous Period.
It had some matrix all over it but the air abrasive unit removed the matrix in short order. This specimen is about the size of a prune. Same specimen in all four pictures. The top two show the fossil's topside and the bottom two show what it looked
This next one is a work in progress. An engraving tool has been used to remove the matrix off some of the fossil. Now an air abrasive is used to clean to the surface detail. This specimen is about the size of a chicken egg.