The piece is carved out of limestone, but not the lighter, quality limestone typical for ancient Egyptian graves. This stone is gray-ish. It was probably treated in the 20th century, perhaps by the forger, to prevent any further flaking, or spalling, on the surface.
How exactly the stone was treated, is yet to be researched, but in the next step you can see that at any rate, there’s no sign of old traces of chiselling.
