Black Ring Set Nature Inspired Color-Change Alexandrite Amethyst Bridal Set Twig Vine Pear Alexandrite Engagement Ring June Birthstone GiftsThe Alexandrite ring Often described by gem aficionados as emerald by day, ruby by night,alexandrite is the very rare color change variety of the mineral chrysoberyl. That is why the color of Alexandrite changes under different lighting conditions DETAILS: Material : 925 Sterling Silver (Hypoallergenic, Nickel Free, Tarnish Resistant) Solid 10K 14k 18k gold, platinum PLEASE choose silver or platinum if you are allergic to nickel. Main Ring : 6*8mm