This is a vintage sterling silver adjustable ring with turquoise stones.
The open band is adjustable with overlapping ends. The band is stamped "925" which is also preceeded by three characters which could be "ONA." The band is also stamped with the eagle 2 logo stamp.
There are 12 small turquoise stones on the outer circle, followed by 7 silver flowers with tiny petals, and right in the middle is a 13th turquoise stone. None of the turquoise stones are missing, but some of the flowers have a missing petal, unless the ring was just handcrafted that way.
The diameter across the top is approximately 3/4" and each stone is slightly over 1/8".