touchstone

Etymology

It is formed from English touch + stone,^[2][3][4] with touch in the Middle English sense of testing metal on such a stone, in Etymonline's account.^[5] The OED thinks it was perhaps modelled on Middle French pierre de touche, recorded before 1389,^[2] and the Shorter Oxford on Old French touchepierre.^[6] The OED compares touchepiarre, recorded in 1474, and Spanish piedra de toque.^[2]

Earliest recorded meaning

A fine-grained dark stone used for building and monuments, especially a black marble: 1482–3, in the Exchequer accounts.^[2][7] The OED notes that despite the dates this sense has probably developed from the stone used for testing gold and silver, recorded in 1530 in Palsgrave.^[2][8]

Semantic evolution

The testing stone worked by comparison: gold or silver was rubbed on it, and the streak it left was compared with those of strips of known composition.^[5] The figurative use, anything that tests the genuineness or value of a thing, followed almost at once, about 1531 in Frith;^[2][5] the 1989 edition of the OED had dated it to before 1533.^[9] It is one of several words that describe trial and testing in terms of tools and materials, a pattern dated to 1500–49.^[10] Johnson (1755) gave both senses and quoted Bacon's Chilon, that gold was tried with the touchstone and men with gold.^[4] The adjectival use, serving as a criterion, is recorded from 1655,^[2] and Merriam-Webster's Collegiate and Unabridged add the sense of a fundamental or typical part of something.^[11][8]

Timeline

• 1482 – fine-grained dark stone used for building, especially black marble.^[2][7]
• 1530 – black stone on which gold and silver are rubbed to test their purity.^[2][8]
• c. 1531 – figuratively, a test or criterion.^[2][5]
• 1655 – adjective, serving as a criterion.^[2]

Meanings

Noun

1. A standard or criterion by which the quality or genuineness of something is judged: For her, honesty was the touchstone of friendship.^[12][8][2]
2. A hard black stone, such as jasper or basalt, formerly used to test gold and silver by the streak they leave on it.^{[13][12][8][2]}
3. A fundamental or typical part or feature of something.^[8][11]
4. (historical) A fine-grained dark stone used for building and monuments, especially a black marble.^[2][7]

Adjective

1. Serving as a criterion or point of reference.^[2]

Related words

• touch
• stone

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
4. ^ a b Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
5. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
6. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
7. ^ a b c Kay, Christian; Roberts, Jane; Samuels, Michael; Wotherspoon, Irené, eds. (2009), Historical Thesaurus of the Oxford English Dictionary, Oxford: Oxford University Press; online edition (2024)
8. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
9. ^ Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
10. ^ Mapping Metaphor with the Historical Thesaurus, University of Glasgow, mappingmetaphor.arts.gla.ac.uk
11. ^ a b Merriam-Webster's Collegiate Dictionary (2003), 11th ed., Springfield, Mass.: Merriam-Webster
12. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins
13. ^ The American Heritage Dictionary of the English Language (1992), 3rd ed., Boston: Houghton Mifflin