SW-197 Fossil RockCone 6 oxidation: Geologically inspired with mottled earth tones, Fossil Rock is an opaque, tan, matte glaze that breaks over texture. Cone 10 reduction: Glaze shifts ivory with soft gray and warm brown marbling. Breaks slate gray over texture. Glaze remains stable. TIP: This glaze is generally stable at 3 coats. Additional coats or increased application thickness may result in glaze movement. We recommend firing our matte glazes to cone 6 to produce