Silica Sand

Often used in clay bodies instead of grog or to augment grog. However, the particle shape should be taken into account. Silica sand particles can be rounded or angular, the latter being more suited to clay bodies. However, the very high thermal expansion of the quartz particles should not be ignored. During temperature changes (like cooling in the kiln), quartz grains act independently in the surrounding brittle matrix, imposing their size changes and weakening the fired item or contributing to dunting.