We have been installing stone backsplashes for many years with no problem. I assume you are talking about a travertine and not marble. Make sure you properly seal the backsplash after installation and that you reseal every 4-5 years with a high quality sealing product. When we seal stone, we do it several times until it does not absorb the sealer any longer. Ask the tile store to recommend a high quality sealer product to use with the tile they are selling you.