I believe this is a Canal 4°C necklace, pink gold. It's for my daughter, but I'm not sure if the case is for a ring or a necklace. I don't know if it's K10 or K14 (probably K10). It has a diamond of about 2mm in diameter. The diamond is very beautiful. I think it's more beautiful than the diamond on my Cartier necklace. The thin chain is cute and doesn't make my shoulders stiff. The chain length is about 40cm.