Emerald says: "§ 23.23(c) It is unfair or deceptive to use the word "laboratory-grown", "laboratory-created", "[manufacturer name]-created", or "synthetic" with the name of any natural stone to describe any industry product unless such industry product has essentially the same optical, physical, and chemical properties as the stone named." Emerald is regarded as the traditional birthstone for May as well as the traditional gemstone for the astrological signs of Cancer. One of the quainter anecdotes about emeralds was told by the 16th-century historian Brantôme, who referred to the many impressive emeralds the Spanish under Cortez had brought back to Europe from Latin
A Study in Emerald of Gaiman's short story collection "Fragile Things," in the collection "New Cthulhu: The Recent Weird", and is available online. The online version takes the form of a Victorian periodical or newspaper, which includes various advertisements that reference characters such as Vlad Tepes, Victor Frankenstein, Spring Heeled Jack, and Dr. Jekyll. In the introduction to "Fragile Things", Gaiman cites Philip José Farmer's Wold Newton Universe, Kim Newman's "Anno Dracula" series (which Gaiman helped create), and Alan Moore's "The League of Extraordinary Gentlemen" as being the major influences of "A Study in Emerald". The story begins with its (as yet) unnamed narrator,