Problems A tablet which comprises solid particles especially magnesium oxide particles as the main component and has excellent shape retentivity with extremely low susceptibility to wearing and chipping. Means for Solution The tablet has a domed shape on each of the upper and lower horizontal surfaces of a cylindrical plate shape wherein the domed shape on each of the upper and lower horizontal surfaces satisfies the following requirements (a)(b) and (c) in the cross-sectional shape including the center line of the cylindrical plate shape: (a) each corner has an angle of 25 to 45� , (b) each corner has a horizontal length of 0.30 to 1.0 mm, and (c) the cup has a depth of 0.6 to 1.2 mm.
