asbestus

1387, fabulous stone, which, when set afire, would not be extinguished; from O.Fr. abeste, from L. asbestos "quicklime" (which "burns" when cold water is poured on it), from Gk. asbestos, lit. "inextinguishable," from a- "not" + sbestos, verbal adj. from sbennynai "to quench," from PIE base *gwes- "to quench, extinguish" (cf. Lith. gestu "to go out," O.C.S. gaso, Hittite kishtari "is being put out"). Meaning "mineral capable of being woven into incombustible fabric" is from 1607; earlier this was called amiant (1420), from L. amiantus, from Gk. amiantos "undefiled" (so called because it showed no mark or stain when thrown into fire). Pliny was the first to make the error of calling this asbestos. Supposed in the Middle Ages to be salamanders' wool. Prester John, the Emperor of India, and Pope Alexander III were said to have had robes or tunics made of it.