Definify.com
Webster 1913 Edition
Touchstone
Touch′stoneˊ
,Noun.
1.
(Min.)
Lydian stone; basanite; – so called because used to test the purity of gold and silver by the streak which is left upon the stone when it is rubbed by the metal. See
Basanite
. 2.
Fig.: Any test or criterion by which the qualities of a thing are tried.
Hooker.
The foregoing doctrine affords us also a
touchstone
for the trial of spirits. South.
Irish touchstone
(Min.)
, basalt, the stone which composes the Giant’s Causeway.
Webster 1828 Edition
Touchstone
TOUCHSTONE
,Noun.
1.
A stone by which metals are examined; a black, smooth, glossy stone. The touchstone of the ancients was called lapis Lydius, from Lydia in Asia Minor, where it was found.2.
Any test or criterion by which the qualities of a thing are tried; as money, the touchstone of common honesty.Irish touchstone, is the basalt, the stone which composes the Giant's causey. This is said also to be an excellent touchstone.