"The Adventure of the Blue Carbuncle" is one of 56 short Sherlock Holmes stories written by Sir Arthur Conan Doyle, the seventh story of twelve in the collection The Adventures of Sherlock Holmes. It was first published in The Strand Magazine in January 1892.

Who was the real owner of the Blue Carbuncle?

John Horner, 26, plumber, was brought up upon the charge of having upon the 22nd inst., abstracted from the jewel-case of the Countess of Morcar the valuable gem known as the blue carbuncle.

What has been the history of the Blue Carbuncle?

During the preparation of the bird for cooking, Mrs Peterson had discovered a blue diamond in the throat of the goose. This blue diamond is the Blue Carbuncle, a precious stone that is being reported as being stolen from the hotel room of the Countess of Morcar.