Gems and Jewels by Egantx7

Question 10

We do not know what kind of gem that it was, but we do know that ex-convict John Horner is falsely accused of stealing it from the the Countess of Morcar, a crime we later discover was pulled off by James Ryder and the Countess' maid. Found in the throat of a goose, which gem was the subject of one of the 12 short stories published in The Adventures of Sherlock Holmes.

Blue Carbuncle