The "point" of the rim of this sherd is rather rounded, and there's a slight indentation on the interior of the rim. I think the vessel was burned post-firing. The bottom of the shoulder is black (in contrast to the top) and extremely hard (harder than the top of the sherd). There is a relief band on the shoulder, and oblique impressions on the band. In addition the the coarse sand in the fabric, there are also pieces of crushed rock.
From Interior to Exterior