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£19.37 GBP
Low stock - 5 in stock, ready to ship

Onyx Black Porcelain (5kg) 1230-1260C

164-ONYX - Onyx Black Porcelain

Onyx Black Porcelain takes on a beautiful black/graphite colour when fired as recommended to the upper part of its firing range. It is highly plastic making it ideal for wheel-throwing and modelling alike. Suitable for tableware. Supplied in a 5kg pack. 

Onyx Black Porcelain is suitable for tableware (food-safe), according to ISO 6486.


  • Firing range: Cone 6-7 (2269º-2295ºF)
  • Biscuit: Cone 06 (1855ºF)
  • Water content: 20%
  • Plasticity (IP Atterberg): 11
  • Carbonate content (CaCO3): 0%
  • Drying shrinkage: 5.4%
  • Firing shrinkage at Cone 6: 10.3%
  • Porosity (water absorption) at Cone 6: 0.0%
  • Dry bending strength: 3.1 N/mm2
  • Fired bending strength at Cone 6: 39.8 N/mm2
  • Thermal coefficient (a25-500ºC): 54.3x10-7ºC-1"