Grog
Definition
Crushed fragments of previously fired ceramic mixed into new clay as temper; recognisable in thin section by their fired-clay texture, which differs from the surrounding unfired or freshly fired matrix.
Related terms
- Ceramic fabric
- The combination of clay matrix and included particles (temper, natural inclusions, and voids) that makes up a fired ceramic; the raw material...
- Dehydroxylation
- The loss of structural hydroxyl groups from clay minerals (principally kaolinite) between about 450 and 600 °C during firing; an irreversible reaction...
- Mullite
- An aluminosilicate phase (3Al2O3·2SiO2) that forms in fired clay above roughly 850-900 °C; its presence in a ceramic records a high-temperature firing...
- Provenance
- In ceramic petrology, the geographic area from which the raw materials (clay and temper) were sourced; distinct from production place (where the...
- Temper
- Material deliberately added to clay before forming to reduce drying shrinkage and firing cracking; common temper types include sand, grog (crushed old...
Explained in
- Brick, Ceramic, and Ceramic PetrologyCrushed fragments of previously fired ceramic mixed into new clay as temper; recognisable in thin section by their fired-clay texture, which differs from the s...