Rose cut diamonds came into being in the 16th century, and differ from modern brilliant cuts as they have fewer facets. A rose cut has 24, and a modern brilliant has 58, so the former diffuses light more softly, while the modern cut has more sparkle.
This ring from Antique Ring Shop has a an 18k yellow gold band with the diamonds set in silver, a common technique for antique pieces. The age of this ring is not specified.
It has diamond weight of .40 carat, and sells for €2,485.