travertine (trav'-er-tine). (a) Biotically and/or abiotically precipitated calcium carbonate (predominantly calcite and aragonite) from spring-fed, heated and/or ambient-temperature waters (Chafetz and Folk, 1984). The spongy or less compact variety is tufa. See also: onyx marble. Syn: calcareous sinter; calc-sinter. (b) A term sometimes applied to any cave deposit of calcium carbonate. (c) A term used inappropriately as a syn. of kankar (Viles and Goudice, 1990). Etymol: Italian "travertino" from Latin "(lapis) tiburtinus" = (stone) of Tibur (Tivoli).