I do not have the expertise to make a reliable recommendation. However, Calacatta Helena Marble is a natural stone that is prone to staining and etching, making it vulnerable to outdoor elements. It may also suffer from weather-related damage and fading over time. Therefore, it is generally recommended to use marble indoors, where it can be protected from harsh outdoor conditions. If you plan to use it outdoors, its best to consult a professional stone installer or a geologist to assess your specific installation and get their advice on whether it will be suitable for your project.