This is a white porcelain tea bowl fired during the Joseon Dynasty. It's a type known as "Katade" (literally "hard hand"). It has a slightly grayish finish. Unlike Bunwon ware, it's a folk craft piece, a vessel for the common people. It's a piece of "getamono" (a term for less refined, often folk-art pottery). There's a noticeable iron oxide coloration around the rim. There are no particularly prominent cracks or chips. Size: Diameter approximately 13.7-14.2 cm, Height approximately 6.7 cm