La pietra del paragone (The Touchstone) is an opera, or melodramma giocoso, in two acts by Gioachino Rossini, to an original Italian libretto by Luigi Romanelli.

[1] Napoleon's Viceroy in Milan, Eugène de Beauharnais, was so impressed by the opera that he wrote to the Minister of the Interior, "You will kindly arrange for Maestro Joachin Rossini to be exempted from military service.

In more recent times, Eduardo De Filippo and Paolo Tomaselli directed a production for the Piccola Scala in 1982, which later toured to the Edinburgh International Festival and the Teatro Donizetti in Bergamo.

At various times, the cast included Margherita Guglielmi, Julia Hamari, Alessandro Corbelli, Claudio Desderi and Justino Díaz, conductor Roberto Abbado.

The ‘’Touchstone’’ of the title is a plan devised by Count Asdrubale to test the sincerity of Donna Fulvia, Baroness Aspasia and Marchioness Clarice, each of whom claims to love the wealthy nobleman.

Immediately most of the house guests transfer their attentions and flattery to the new arrival, failing to recognize that it is Asdrubale in heavy disguise and using a ridiculous fake accent.

When he is finally persuaded to leave his private rooms (the "wealthy oriental creditor" having departed) they promise their continued loyalty and financial support.

Asdrubale invites his guests to go hunting and Pacuvio further demonstrates his cowardly nature by panicking when a storm blows up and losing his gun and other possessions in a headlong dash back to the villa.

As a final act he asks Fabrizio to deliver a note to the young officer for Clarice, regretting his ridiculous jealousy.