- 1A piece of fine-grained dark schist or jasper formerly used for testing alloys of gold by observing the color of the mark that they made on it.Más ejemplos en oraciones
- Small black stones were used as touchstones to test the colour, and hence purity, of gold.
- ‘To touch’ in reference to fine metals such as gold refers to the touchstone used to test the purity of the metal.
- The same example can be cited: in spite of producing unlimited quantities of gold, the touchstone remains the same.
- 1.1A standard or criterion by which something is judged or recognized: they tend to regard grammar as the touchstone of all language performanceMás ejemplos en oraciones
- We see the standard touchstones - the Wailing Wall, the Dome of the Rock - but we also see the streets, Jerusalem as a town, a city where Jews and Arabs both live.
- By the Second World War the toleration of COs had begun to be recognized as a touchstone of mature liberalism.
- Nor has he challenged the appellant's case that the requirements of the Convention provide a touchstone for judging the rationality of his decision and the policy pursuant to which it was reached.