Chryse and Argyre
In Book 6, chapter 23 of his Natural History, concerning the regions near the Indus River, Pliny the Elder (23–79 CE) wrote that "Beyond the mouth of the Indus are the islands of Chryse and Argyre, abounding in metals, I believe; but as to what some persons have stated, that their soil consists of gold and silver, I am not so willing to believe that."
Some five or six centuries later, in section XIV.vi.11 of his encyclopedic Etymologies, Isidore of Seville (c. 560–636) repeated much the same information: "Chryse and Argyre are islands situated in the Indian Ocean, so rich in metal that many people maintain these islands have a surface of gold and silver; whence their names are derived." This was almost certainly taken—like much else in the Etymologies, as Isidore freely admitted—directly from the Natural History. Both of these Latin works, the Naturalis Historia and especially the Etymologiae, were widely read in Europe throughout the Middle Ages, and this ensured the survival of the legend of the Gold and Silver Islands until the beginning of the Age of Discovery.
As European geographers gathered more reliable information about the Indian Ocean, the purported location of Chryse and Argyre shifted farther and farther east to the fringes of the known world. By the time Martin Behaim created his Erdapfel globe in 1492, the islands were though to be near Japan, possibly because Marco Polo had claimed Japan itself (which he called Cipangu) to be rich in gold and silver; Behaim is known to have used both Pliny and Marco Polo as sources.
The discovery of the Americas changed everything. European explorers in search of fabled lands of gold now sailed west for El Dorado, instead of east to Cipangu. The works of Isidore of Seville fell out of fashion, and the islands of Chryse and Argyre slowly faded from the popular imagination.
In 1877, however, they were recalled to life by the astronomer Giovanni Schiaparelli, who used the planetary opposition of that year to begin mapping the planet Mars. As an expert in ancient astronomy and geography he was very familiar with classical legends and fabled lands, and used them to name the features he could see through the telescope. He assumed that dark areas might be low flat "seas", as they are on the Moon, while "land" would be lighter. In particular he noted several light patches that he took to be islands; he named the most striking circular one Hellas (for Greece), and two others Chryse and Argyre.
It was only with the observations made from Martian orbit by Mariner 9 in 1972 that it became clear that these light areas were not islands at all, but depressions carpeted with light windblown dust. Chryse is really a low flat plain, but the name has been kept, and it is now known as Chryse Planitia, "Chryse Plain". Argyre (like Hellas) is in fact a broad impact crater, and is now Argyre Planitia, "Argyre Plain", which in turn has given its name to one of the cartographic quadrangles of the Martian atlas.
- Pliny the Elder. Bostock, John; Riley, H.T., eds. "The Natural History, Book 6". Perseus Digital Library. Tufts University.
- Isidore of Seville. Barney, Stephen A.; Lewis, W.J.; Beach, J.A.; Berghof, Oliver, eds. "The Etymologies of Isidore of Seville" (pdf). sfponline.org. Cambridge University Press. p. 294.
- "The Behaim Globe" (html). cartographic-images.net. Retrieved 29 Nov 2016.
- "Surface Features on Mars: Ground-Based Albedo and Radar Compared With Mariner 9 Topography". 79 (26). Journal of Geophysical Research. 1974: 3907–3916. Bibcode:1974JGR....79.3907F. doi:10.1029/JB079i026p03907.