A limestone (not technically a marble!) that ranges from dark greys to coral regs, travertine has been used as masonry blocks or fine finishes for centuries. While it usually comes with pockets and troughs—a result of its geological formation—it can be buffed smooth. While perhaps most popular as a mosaic, it can be used to sheathe exteriors, floors, walls, and more. Explore this versatile construction material in these 7 modern homes!