Nimrud lens (rock-crystal disc)
Lente de Nimrud (disco de cristal de roca)
- Date
- c. 700 BCE · confidence medium
- Place
- Nimrud (Kalhu), Nineveh, Iraq
- Credited to
- Neo-Assyrian craftsmen
- Field
- Communication
⚠️ Disputed: the sources disagree.
What it is
A polished rock-crystal disc with one convex face, found by Layard in the North-West Palace at Nimrud. It focuses sunlight, and it has been proposed as a magnifier or fire-starter, although it may simply have been an inlay ornament.
Brewster (1852) proposed it was a lens; today it is debated whether it was optical or merely decorative (furniture or ivory inlay). There is no proof it was used for magnification.
What it led to
- hypotheses about magnifying lenses in antiquity (seal-cutting and miniature work)
- historiographical debate on the origins of instrumental optics before spectacles