This is the story in which the rare garnet turns up in a Christmas goose.
Based on the black and white Sherlock Holmes movies she'd seen on TV, Sarah thought Doyle might be sort of a stuffy writer. She was delighted to find that the stories are lighthearted and accessible, which helps her understand the mass appeal in their own time and the liveliness of the most recent movie version. She didn't like the movie much, but she understands it better now, having read the original stories. And they are a fun read, right after college and starting a fulltime job, each one very satisfying but not taking too much of her time.
We chatted about the word "carbuncle" which always calls up an icky hard callous dripping pus, far cry from a garnet but not so far, really, as the root word means "coal" and both the red (or deep purple or blue) gemstone and the bacterial wound are hard, compact.
Carbuncles appear elsewhere in literature, mostly in their gemstone sense, but not always! Wikipedia conveniently tells us there are carbunckles in The Picture of Dorian Gray, by Oscar Wilde, "The Great Carbuncle," by Nathaniel Hawthorne, and the Bible.
Art by Herbert Zohl! I think he is making this available as a print you can buy.