n. 试金石, 检验标准

[ noun ]
a basis for comparison; a reference point against which other things can be evaluated
<noun.communication>
the schools comply with federal standardsthey set the measure for all subsequent work

Touchstone \Touch"stone`\, n.
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.