The Carbuncle by Jorge Luis Borges

In mineralogy the carbuncle, from the Latin carbunculus, ‘a little coal', is a ruby; as to the carbuncle of the ancients, it is supposed to have been a garnet.

In sixteenth-century South America, the name was given by the Spanish conquistadors to a mysterious animal mysterious because nobody ever saw it well enough to know whether it was a bird or a mammal, whether it had feathers or fur. The poet-priest Martín del Barco Centenera, who claims to have seen it in Paraguay, describes it in his Argentina (1602) only as ‘a smallish animal, with a shining mirror on its head, like a glowing coal. ' Another conquistador, Gonzalo Fernández del Oviedo, associates this mirror or light shining out of the darkness two of which he glimpsed in the Strait of Magellan with the precious stone that dragons were thought to have hidden in their brain. He took his knowledge from Isidore of Seville, who wrote in his Etymologies: