Yes, it is possible, but not recommended, to install an artificial stone backsplash over existing tile. Proper surface preparation is crucial for a successful installation. The existing tile should be clean, dry, and in good condition. The surface may need to be roughened or primed to ensure proper adhesion of the artificial stone. It is recommended to consult with a professional or follow the manufacturer’s instructions for the specific artificial stone product being used to ensure a proper and durable installation.