[1] To avoid such thermal shock faults, cooling rates not exceeding 50 °C/hour have been recommended.
[2] At 870 °C quartz ceases to be stable but, in the absence of fluxes, does not alter until a much higher temperature is reached, when, depending on the temperature and nature of the fluxes present, it is converted into the polymorphs of cristobalite and / or tridymite.
This puts the glazes into compression and so helps prevent crazing.
[4][5][6] The size of the silica particles influences inversions, conversions and other properties of the ceramic body.
[7][8][9] The presence of other ceramic raw materials can influence the thermal behaviour of quartz, including: