Careful controlling of the heatworks to reach around 1,250 degrees Celsius is necessary to melt the glaze components completely but retain some seeding agents. The temperature is then brought down to allow the zinc oxide and silica to form crystals around a seeding point. The shapes and sizes of the crystals are controlled by the temperatures and duration they are held at. Because this is a mimicry of nature, the randomness dictates that no two pieces will ever be identical.