A vitreous crucible for holding semiconductor material during a moncrystalline ingot growing process has a sidewall. Part of the sidewall is coated with a devitrification promoter and part of the sidewall is substantially free from devitrification promoter coating. When the crucible is heated as it would be during an ingot growing process, the devitrification promoter induces crystallization of portions of the sidewall, thereby forming enhanced stiffness sidewall portions. Areas that are substantially free from devitrification promoters remain vitreous and are softened by the heat. These become stress accommodating sidewall portions. Flow of the vitreous material in the stress accommodating sidewall portions relieves stresses that would otherwise build up in the sidewall.
