Speckled Buff Stoneware Cone 6. This is a medium texture tan/buff color plastic stoneware with brown and black specks in oxidation. It is well formulated for throwing and hand building. It fires from cone 6-10 and is approaching vitrification at cone 10. Speckled buff is suitable for oxidation firing and is not recommended for reduction firing. Fires Between Cone 6-10, 2232-2345° F. Shrinkage rate is Cone 6 - 12.6%, Cone 10 - 12.8%. Best use is Throwing, Oxidation. Color is tan with dark speckles.