Tachylite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Travertine is a type of sedimentary rock formed when a river carries or transports pieces of broken rock which then undergo sedimentation. They are then subjected to high temperature and pressure hence forming travertine rock.