Mars Crystal is a highly fluid, dark brick red glaze with silvery, iridescent crystals. Opaque and breaks darker.Apply to: Cone 04 BisquewareNumber of coats: 4 coatsThis glaze performs best at cone 6 but can be fired to cone 5. For best results, leave the inside or back of the form unglazed.Can be fired in a normal medium-speed firing with no special cooling schedule required. To take this glaze to the next level, use a controlled cooling schedule for increased crystal growth.These glazes are prone to running so we recommend stopping your glaze about half an inch above the foot. You can also use a drip tray or soft bricks to protect kiln shelves.Is this glaze food safe? Yes, but due to durability, these glazes are not recommended for food surfaces.