Unusual dark green turquoise Royston? Navajo sterling modernist ring

Unusual modernist Navajo ring with an asymmetrical mid-century design in sterling silver with a dark green turquoise (likely Royston) in a zigzag setting. Hallmark: STERLING. Unsigned. Size 6. Has the patina and very small scratches expected from a vintage ring that has been worn and loved. *** Any other objects in photos are for styling purposes and are not included in this listing. I do my best to research and determine the items' provenance, and I will *never* knowingly attempt to pass a fake or replica off as an original. Honesty and transparency are extremely important to me. However, I am not a professional authenticator and can make no guarantees as to the authenticity of what I sell. I currently do not accept returns unless the item is different than described - please contact me with questions before purchasing! For the sake of our planet I reuse packing materials whenever possible. Thank you for supporting my small business!