C19: from German Kalksinter, from Kalk lime + sinter dross; see chalk, sinter
travertine in British English
or travertin (ˈtrævətɪn)
noun
a porous rock consisting of calcium carbonate, used for building
Also called: calc-sinter
Word origin
C18: from Italian travertino (influenced by tra-trans-), from Latin lapisTīburtīnus Tiburtine stone, from Tīburs the district around Tibur (now Tivoli)