I bought this ring in an auction (Goodwill) It was described as Native American turquoise ring (unknown), I fell in love with the ring, that I didn't bother to do any research on it or who made it or if it is a natural stone or stabilized. I have seen some sites that show the hallmark is either Rita Dawes or John Delvin or even Darrel Morgan & Calvin Desson; but their mark is either with the D under STERLING or STERLING upside down from the D. This one is with the marking all horizontal "STERLING D" I have no clue on who made this beauty, I wish I knew who, to give him/her credit (spiritual).
To whom ever gives me actual clues, I will send them genuine blessings (mayan) as a REWARD!!!
Take care people!