The head looks smaller in the photos then it is, it's like a small hand sledge

Looks like a hammer for texturing stone. Something used by a mason.

Hello, Sudsy . It is a Bush Hammer  or Bushing Hammer , name varies by manufacturer . As Redneck Albertan wrote , for texturing stone .

Or clean it up, and tenderize an entire side of beef/half pig!

Once again, this site comes though

Thanks guys !
And Happy New Year

What kind of finish is obtained with this hammer?  My son works sometimes in stone.  Maybe its something he could use.
Thanks
Al

It will be similar to the edges of a granite tombstone.  A skill level is involved to get consistant results.

as noted above: "Bushing Hammer" - they came in various styles. some look like meat tenderizing hammers. some are odd-looking affairs with multiple "blades" which are replaceable.

see https://archive.org/details/TrowHoldenCatalog11/page/n27/mode/2up - page 26

I always thought they were for smoothing stone.  Alvin Sellens Dictionary of American Hand Tools says " for breaking stone and removing projections to flatten a stone.  There is another variety that has stacked blades.  It can be taken apart and the blades sharpened.