This is such a pretty and delicate looking vintage ring by Sarah Coventry jewelry, that dates to the mid 1970s.  A simple design called "Golden Lace", the gold tone metal band is entirely filigree.

 A book piece shown in the book “Emmons & Sarah Coventry Jewelry Fashion Show” by Deborah A. Robinson on page 115.

The size is adjustable and is currently about a 6 1/2.  Signed SARAH on the interior.