Keene's cement plaster

Keene's Cement Plaster or Keene's cement is a hard plaster formulation, primarily used for ornamental work. Alternative names are Martin's cement and Parian cement. It is a calcined formulation of regular calcium sulfate plaster with an alum admixture. The compound gives a hard finish that can be polished. The product was developed by Richard Wynn Keene and patented in 1838.^[1][2]

References

1. Curl, James Stevens; Wilson, Susan (2016). Oxford Dictionary of Architecture. Oxford University Press. p. 407. ISBN 978-0-19-967499-2.
2. The Repertory of Patent Inventions, new series, vol. 10, June–December 1838, pp. 229–232.