Cone 6: Robin’s Egg is a greenish-blue matte glaze that contains a sand-colored crystal. As the crystal melts, a small sandy-brown bloom will appear in the glaze, producing a mottled, textured finish. Cone 10: Semi-gloss finish with variegated blue/light blue and crystals. TIP: SW-105 Frost Blue is the base glaze. For a lighter crystal effect, you may try applying two coats of SW-105 Frost Blue with a third coat of SW-116 Robin's Egg.