Gresham and the Pearl
When Queen Elizabeth visited the Exchange, Sir Thomas Gresham, it is said, pledged her health in a cup of wine containing a precious stone crushed to atoms, and worth £15,000. If this tale is true, it was an exceedingly foolish imitation of Cleopatra (q.v.).
Here fifteen thousand pounds at one clap goes Instead of sugar; Gresham drinks the pearl Unto his queen and mistress. Pledge it, lords.
Heywood. If You Know Not Me You Know Nobody.
To dine or sup with Sir Thomas Gresham. (See under Dine.)
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894