Travertine, many layers... like an onion.
Travertine is another stone similar to Limestone but with enough difference in how it's formed and the density it has that it is classified as Travertine. Travertine is made in hot springs where the water evaporates quicker, leaving behind thin layers of deposits that compress and form into stone. It's much more dense than Limestone but can still have the same issues we find in Limestone. Usually, because the stone can keep water out better than limestone, the organic growth and other problems we see tend to remain closer to the surface of the travertine and can be corrected using the same methods as limestone. We still recommend a treatment process to help keep as much water out as possible due to the voids created by fossils that tend to be more prevalent in Travertine.