This proverb warns that appearances can be deceptive, and not everything that looks valuable or appealing is genuinely so. It advises caution against judging based on surface allure, often applied to people, opportunities, or objects that seem promising but lack substance. The phrase promotes discernment and skepticism.

The phrase comes from Shakespeare’s *The Merchant of Venice* (1596), where a scroll reads: ‘All that glisters is not gold.’ Earlier versions exist in Latin (*Non omne quod nitet aurum est*) and Chaucer’s *The Canterbury Tales* (1387): ‘But al thyng which shineth as the gold / Nis nat gold.’ The proverb reflects medieval alchemy’s fascination with gold and deception. By the 19th century, ‘glitters’ replaced ‘glisters,’ and the phrase was popularized in English literature, including by John Dryden and Charles Dickens.