There are linear marks on the foot of the piece. I initially thought they were from thread cutting, and that it was from China, but upon closer inspection, they weren't. I believe it's from the late Goryeo period, around the 14th century. The single carved line on the rim is likely due to the period of national turmoil. The celadon color is as shown in the images, and I believe this hue is appreciated by tea ceremony enthusiasts. I'm unsure whether to call it celadon, or ash glaze. There is a careful repair, likely to a crack. There is no "nakigoe" (a specific sound defect), and it produces a high-pitched sound similar to porcelain. There are small scratches on the foot, and some areas appear to have adhered to something, as shown in the images. The box was likely prepared in the early modern period, but I don't know if it's original to the piece. The paper label is simply my own management tag. Diameter: Approximately 8.2cm Height: Approximately 9.3cm The size is approximate. The actual item may differ slightly in color from the images. As it is an old item, there are age-related scratches and stains.