Discovered in 1850 by English archaeologist Austen Henry Layard at the ancient Assyrian palace of Nimrud, in modern-day Iraq, the Nimrud Lens is a curious piece of rock crystal dating back to the late 8th century B.C. Roughly ground into a slightly oval shape, its size is 38 millimeters in diameter and has a focal point and length equivalent to a 3× magnifying glass. Its function is unclear, and it could have been a magnifying glass or a burning glass, a tool used to start fires by concentrating sunlight. As…
