Lot of 4 gold rings with diamonds

a) one 18k yellow gold spiral motif ring, set with a central diamond, round shape, brilliant cut, 0.15 ct; Hallmarked with the  french mark for gold and serial number "23398". Size IT 8 - size US 4 1/2;
b) one ring, floral motif set with a central diamond, round shape, old european cut, 0.25 ct. Size IT 14 - size US 6 1/2;

c) one 18k yellow gold ring with a central diamond, round shape, old european cut, 0.10 ct. Hallmarked with the gold french mark. Size IT 18 - size US 8 1/2; 
d) one solitaire ring with a central diamond, round shape, rose cut. Size IT 13 - size US 6 1/2;

Total weight 9.1 g.
Item condition grading: **** good.