Crystalline is a type of ceramic glaze where crystals grow inside the glaze. In comparison to other glazes, crystalline is one of the most difficult to achieve with many ceramists finding it fickle, unpredictable and time consuming with a very low success rate. As such, there are only a small number of ceramists in Australia that create them professionally. The Crystalline glaze was discovered in China hundreds of years ago and as such Chinese ceramists have an extensive understanding of the glaze. Because Chinese ceramists tend to work with their families in small groups, knowledge of important factors determining the formation of crystalline is kept within the family and shared only amongst generations like a well-kept secret. The formation of crystals is determined largely by two conditions: the glaze and the firing temperature. The glaze is usually a silica and zinc mix, although variations on this do exist. For the crystal to actually blossom, the glaze must be fluid, and this in itself is a difficult achievement. If the glaze is too fluid it will simply run off the pot, destroying the shelves of the kiln. If the glaze is too thick it can impede the movement of the glaze resulting in no crystals forming. The firing process of crystalline is equally arduous and the ceramists must pay fastidious attention to the firing temperature. Firstly the kiln is heated to 1350° C to melt the glaze mix. Then depending on the type of crystal desired the temperature of the kiln is slowly lowered at such a rate for the crystal to ‘blossom’. As most Chinese ceramists use gas-fired kilns, they can rely on traditional methods such as ‘peep holes’ in the kiln to watch the colour of the flame to ensure the crystals form. Once the desired crystal is formed the piece is then removed, though most full crystal formations take between 6 to 12 hours. Generally, the larger the desired crystal, the longer it remains in the kiln. Other techniques such as raising the crystal, so that it becomes tangible, involve removing the piece from the kiln and then replacing it again and repeating this process many times over. The Chinese discovered this technique by accident and continue to experiment with its possibilities today. The end result of crystalline is always unique. Of those pieces that do posses the right glaze consistency and survive the high temperature of the kiln, the finish is always striking. Many ceramists agree that despite its difficulty and low success rate the Crystalline glaze is by far one of the most artistically fulfilling glazes to achieve. Click to view the Crystalline range