Black opal glaze effect

Black opal glaze effect on the wavy vase.  Crystalline glaze where the crystals grow in the kiln. crystalline glaze the glaze is a specialist type of glaze where zinc silicate crystals form in the glaze during the kiln firing process using a complex schedule with several temperature ramps to create different crystal growth formations. the amount of time held at each temperature allows the crystals to form and contributes to the size of the crystals they appear randomly in the glaze making each piece unique