Rose diamond crowned heart betrothal ring c.1760. 
High-carat gold Rococo scrolled decorative shank  and high-carat gold chased gold crown, the three rose diamonds set in silver cut-down settings.
Continental origin. For similar examples see No's 903 and 905 Alice and Louis Koch Collection. The settings strongly resemble French Provencal setting of the 18th century.
Size 6.5