In the Sherlock Holmes story “The Adventure of the Blue Carbuncle,” where is the precious stone first found?

In “The Adventure of the Blue Carbuncle,” the precious stone is first found inside a Christmas goose.

The story was first published in 1892 and collected in The Adventures of Sherlock Holmes. On the day after Christmas, Henry Baker loses a hat and a goose during a street disturbance. Peterson, a commissionaire, brings the recovered items to Holmes. When the goose is cooked, Peterson discovers the Blue Carbuncle of the Countess of Morcar inside it.

The jewel had been stolen from the Hotel Cosmopolitan, and suspicion had fallen on John Robinson, an attendant at the hotel. Holmes traces the goose through London markets to its supplier and then identifies James Ryder as the actual thief. Ryder confesses after Holmes confronts him but chooses not to send him to prison.

The blue carbuncle is a fictional gemstone in the story. A carbuncle is traditionally a red gemstone, so the phrase is a literary name rather than a precise modern gemological classification. The Christmas setting is why the case is often included in holiday reading lists.