The Legend of the Golden Fleece
The story is included in Metamorphoses by the Roman poet Ovid.
Jason first suggested the task of fetching the Golden Fleece from distant Colchis to King Pelias, as he believed it to be an impossible quest. Pelias had tricked Jason, assigned the task to him, and suggested he make good preparations. Jason accepted the task, as he possessed a thirst for fame and glory. Heroes from all over Ancient Greece flocked to join the expedition, although Colchis was situated a long way away and was guarded by as giant snake. Georgius Agricola provided one explanation for the Golden Fleece.
"The Colchians placed the skins of animals in the pools of springs; and since many particles of gold had clung to them when they were removed, the poets invented the 'Golden Fleece' of the Colchians. In like manner, it can be contrived by the methods of miners that skins should take up, not only particles of gold, but also silver and gems."
Herbert Hoover added these notes to Agricola's account
"Colchis, the traditional land of the Golden Fleece, lay between the Caucasus on the north, Armenia on the south, and the Black Sea on the west. If Agricola's account of the metallurgical purpose of the fleece is correct, then Jason must have had real cause for complaint as to the tangible results of his expedition. The fact that we hear nothing of the fleece after the day it was taken from the dragon would thus support Agricola's theory. Tons of ink have been expended during the past thirty centuries in explanations of what the fleece really was. These explanations range through the supernatural and metallurgical, but more recent writers have endeavoured to construct the journey of the Argonauts into an epic of the development of the Greek trade in gold with the Euxine. We will not attempt to traverse them from a metallurgical point of view further than to maintain that Agricola's explanation is as probable and equally as ingenious as any other, although Straabo (xi, 2, 19.) gives much the same view long before."