Back-butter the marble tiles as well as spreading adhesive on the wall. Use a flexible white adhesive if the marble is translucent. If you're not bullnosing, perhaps use a wide trim.
The following shows you some threads on the forum related to marble: https://www.google.co.uk/webhp?sour...8#q=site:tilersforums.com+adhesive+for+marble
The following shows you some threads on the forum related to marble: https://www.google.co.uk/webhp?sour...8#q=site:tilersforums.com+adhesive+for+marble