touchstone (plural touchstones)
() (A synonym for a type of stone?) "The design of Margaret Beaufort's tomb is only un-Italian in that it is of the free standing altar type traditional to England. All of touchstone, it has on the four sides roundels, separated by fluted Composite pilasters, of ribboned bay wreaths enclosing escutcheons in gilt bronze." James Lees-Milne, Tudor Renaissance (B.T. Batsford Ltd, 1951, p. 29).
- (figuratively, by extension) A standard of comparison or evaluation.
- The foregoing doctrine affords us also a touchstone for the trial of spirits.