Mount is Sterling Silver. Crystal colors are surprise could be one of the  following,
Amazonite, Amethyst, Black Onyx, Carnelian, Clear Crystal, Green Aventureine light, Green Aventurine dark, Green Onyx, Howlite, Howlight Dyed (color of Torquois), Labradorite, Lapis, Rainbow smooth, Rose Quartz, Sodalite, Tiger Eye, Unakite, Yellow Aventurine