A slurry composition for a mold and method of use thereof. The slurry composition includes about 45-80% by weight alumina, about 10-30% by weight silicon carbide, and about 10-50% by weight colloidal silica. In one aspect, the alumina component comprises a material selected from the group consisting of brown fused alumina, white fused alumina, tabular alumina, calcined alumina, and mixtures thereof. In another aspect, the composition includes fumed silica at 2-5% by weight. The composition may also include a setting agent at 0.05-2% by weight.