a test or criterion for the qualities of a thing.
a black siliceous stone formerly used to test the purity of gold and silver by the color of the streak produced on it by rubbing it with either metal.

Origin of touchstone

First recorded in 1475–85; touch + stone

Synonyms for touchstone Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for touchstone

Contemporary Examples of touchstone

Historical Examples of touchstone

  • Fictions or realities, could they survive the touchstone of this atom of common sense?

  • Descartes therefore made evidence the touchstone of certainty.

  • I shall have a double respect for his opinion, for this is the touchstone of a man's honesty.

    Homeward Bound

    James Fenimore Cooper

  • For Vere's eyes were surely a touchstone to discover honesty.

    A Spirit in Prison

    Robert Hichens

  • The answer does not satisfy Socrates, who fears that he is losing his touchstone.



British Dictionary definitions for touchstone



a criterion or standard by which judgment is made
a hard dark siliceous stone, such as basalt or jasper, that is used to test the quality of gold and silver from the colour of the streak they produce on it
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for touchstone

late 15c., from touch (v.) + stone (n.). Black quartz, used for testing the quality of gold and silver alloys by the color of the streak made by rubbing them on it. Cf. also basalt. Figurative sense is from 1530s.

Online Etymology Dictionary, © 2010 Douglas Harper