Note 648 — BOOK XXXIII. THE NATURAL HISTORY OF METALS.647
John Bostock translation
“Ipsæ opes.” The metals were looked upon by the ancients as the only true riches. It is in this sense that Ovid says, Metam. B. i.: “Effodiuntur opes, irritamenta malorum.” Pliny applies the term “pretia rerum” to metals, as forming the unit of value.