The present invention provides a curable composition allowing a cured product having high aesthetic quality, strength and durability along with having high surface lubricating property to be formed. The curable composition according to the present invention comprises: an inorganic powder and a polymerizable monomer. The inorganic powder contains a spherical crystallization control powder. The spherical crystallization control powder has a silicon dioxide content in the range of 97 to 100 mass %. An amorphous portion and a crystalline portion are mixed within the spherical crystallization control powder. A refractive index difference is not more than 0.05 between the spherical crystallization control powder and a cured product obtained by curing only constituents other than the spherical crystallization control powder.
