I would call it Rock, seen a few of this style, can't remember The actual name. At first glance sure looked like a Royal Copley, but usually their feet are not as tall. But maybe look at the Royal Copley stuff, This would be considered a Window Planter, and Royal Copley is known for that. I will have to dig up a pic of the bottom of Royal Copley stuff, These can be hot items. Also this is for sure mid century pottery, and is very unique.