Platinum Gemstone Semi Mount. Beautiful with Blue Sapphire, also would look great with Pink Sapphire, Emeralds, or Rubies. The Platinum ring is available in many size options, price shown is for the 1/4ct center selection. Email firstname.lastname@example.org for a center diamond price list, we have thousands of diamonds to choose from. Our price shown is for the engagement portion and does not include the matching band.