3D printable ring, castable in gold, silver, etc. Accepts 6x3 and 8x4mm sapphires (https://www.etsy.com/listing/632047745/lab-created-blue-sapphire-corundum) with bottom facet ground down until total depth is 2mm (custom order, minimal if any markup).Size 8.5, different sizes available upon request (will make alternate size available within 24 hours in most if not all cases)