Hawthorne fireclay is really more of a stoneware clay
This is test-result data as reported from an account at Insight-live.com from a test done in 2002. The numbers in the first column in the shrinkage absorption section are the specimen numbers, they bars are labelled (on the right) with them. This clay is already quite dense and vitreous by cone 10 oxidation and reduction (having a 3% porosity) and it has a high fired shrinkage (more than 8%). Drying shrinkage is very low and its drying factor (performance) is good (even though it is quite plastic). The manufacturers data sheet shows higher firing shrinkage figures, however their numbers are actually total fired+drying shrinkage.