I am not sure if it is 1/5 10k Gold. Or if it is 10k gold. I believe 1/5 gf would be more pure than 10k so I'm not sure what it says on the back as shown in the pictures above. This is a cool pin. Buy it for what ever you believe it to be. It clearly says 10k.The letters above it is not as clear. If you have any questions feel free to message me. Remember if you are interested in saving money on the item or also on shipping -> Be sure to bundle items or make me a reasonable offer. Thank you for looking at my items jewelry lot 2 -21