Thanks for reaching out Teresa, I am so glad you found us!
There are two possible. candidates for the K 18 mark that are stamped on your earrings which are in direction opposition to each other.
1. The K18 mark indicates your old Italian Rose Gold. earrings are made of 18-karat gold, meaning the metal is 75% pure gold and 25% other metal alloys. While 18K is the worldwide standard, K18 may suggest an Asian or Japanese export, though it is often used internationally on fine jewellery.
2. K18 can indicate the piece is a plated fake. Be aware that marks like K18 RGP (Rolled Gold Plate) or K18 GP (Gold Plated) mean the item is a base metal with only a thin layer of gold.
