Traditional terracotta (calcareous) earthenware clay. Its calcium carbonate content (19%) allows an interesting palette of colours, from pink to straw colours, depending on the firing temperature and atmosphere.
Its thermal expansion coefficient is ideal for standard pottery glazes, in both single and twice fired processes. It displays high resistance to frost and environmental degradation make it ideal for pieces exposed to the outdoors (garden pots, tiles, etc).
Available in an extruded body, suitable for wheel-throwing, modelling and shaping processes (as well as extruding and pressing etc).
Firing range*: 990-1085ºC / Cone 07-04
Water content (throwing): 22%
Plasticity (IP Atterberg): 18
Carbonate content (CaCO3): 22%
Drying shrinkage: 7.8%
Firing shrinkage (1000ºC): 0.8%
Porosity (water absorption at 1000ºC): 14.3%
Dry bending strength: 9.9 N/mm2
Fired bending strength (1000ºC): 31.2 N/mm2
Thermal coefficient (25-500ºC): 80.3x10^-7ºC^-1
(*) Firing range recommended for the clay to develop its best performance, both in terms of technical and safety characteristics, under conventional firing conditions. The colour samples may show temperatures outside the recommended range to provide a broader view, but these are pieces fired under controlled conditions. Cone equivalence according to Orton table for self-supporting cones, regular-SSB and 150ºC/hr heating rate.