PROBLEM TO BE SOLVED: To obtain a gypsum composition which provides a colored gypsum setting object of which the surface does not undergo change in color and color degradation even when contacting with a disinfectant.SOLUTION: The gypsum composition is prepared by compounding bismuth vanadate with hemihydrate gypsum at 0.0001 to 2 parts by weight per 100 parts by weight of the hemihydrate gypsum.COPYRIGHT: (C)2007,JPO&INPIT【課題】消毒剤に接触しても表面が変退色しない着色石膏硬化体を与える石膏組成物を得る。【解決手段】半水石膏にバナジウム酸ビスマスを,半水石膏100重量部あたり0.0001~2重量部で配合して石膏組成物とする。【選択図】なし