Locket marked 270 Gold

I have this pretty locket which has the stam0 270 Gold on it. I have tried to photograph it but not very successfully, but with my Loupe it is definitely 270 GOLD.  I cannot find any reference to this , can anyone assist please with what carat of gold it is and what age it would be. Thank You

Possibly 970 mark for mexican silver, and gold plated.

Thank you for that but it is definitely 270, and I am almost certain that it is Gold and not plated.

The smallest fineness for gold is 375 = 9ct, in my opinion, these marks are not indicating the item is made of gold.

Does it open? Maybe the hinge style would date it

Hello, Yes it does open here is a photo of the hinge

Is that green colour verdigris? If so, it's gold plated copper. Probably late Victorian judging by the decoration. The 270 might refer to the thickness of the gold plate. It's possibly a very thin layer of rolled gold rather than a 'dipped' electro-plating.

Thanks for your responses, no it's not verdigris, it's just filthy dirty. I will give it a clean.