This vaguely floral garnet pin is a souvenir from the 1835 appearance of Halley's Comet, a "short-period" (i.e. frequently recurring) comet whose appearances have been recorded by humans since 240 BCE. It was the British astronomer Edmund Halley who gave the comet its name in 1705, when he realized it was the same celestial entity whose passage had been noted by the ancient Greeks, Babylonians, and, most famously, the medieval English, who took its 1066 appearance as an omen of political strife. (Their king, Harold II, was murdered in battle by William the Conqueror later that year.)