The Nimrod Lens
The Nimrod Lens is a 3,000 year old rock crystal piece found at the Assyrian palace of Nimrod. It may have been used as a magnifying glass. The discoverer of the lens also found minute inscriptions on other artifacts that he suspected were made with an optical aid. Lenses like this one may have been used to help celators (master engravers) see well enough to etch the tiny artistic engravings into iron dies for minting ancient coins.