In the novel "The Three Musketeers", what did Queen Anne present to the Duke of Buckingham?

"The Three Musketeers" is a French historical adventure novel written in 1844 by French author Alexandre Dumas. It is in the swashbuckler genre, which has heroic, chivalrous swordsmen who fight for justice.

Set between 1625 and 1628, it recounts the adventures of a young man named D'Artagnan (a character based on Charles de Batz-Castelmore d'Artagnan) after he leaves home to travel to Paris, hoping to join the Musketeers of the Guard.

The plot of the first part of "The Three Musketeers" revolves around 12 diamond studs that Queen Anne d'Autriche gives to the Duke of Buckingham. D'Artagnan hires a servant named Planchet, finds lodgings, and reports to Monsieur des Essart, whose company is a less prestigious regiment in which he will have to serve for two years before being considered for the musketeers.

Shortly after, his landlord speaks to him about the kidnapping of his wife, Constance Bonacieux. When she is presently released, D'Artagnan falls in love at first sight with her. She works for Queen Anne of France, who is secretly having an affair with the English duke of Buckingham. The king, Louis XIII, gave the queen a gift of diamond studs, but she gives them to her lover as a keepsake. Cardinal Richelieu, who wants war between France and England, plans to expose the tryst and persuades the king to demand that the queen wear the diamonds to a soirée that the cardinal is sponsoring.