Upvote:4
Officially, anything you bring into the EU is subject to declaration and payment of import taxes (VAT, the rate of which depends on the country you arrive in) and duties (which depend on what it is, the country of origin, etc.).
There is a duty-free allowance, but the value of the item exceeds that allowance.
Personal items that you bought in the EU and already paid taxes on, or that you have had for a while are exempted, though the onus is on you to prove the circumstances, and none of those apply here.
So the real official answer is that you should go through the red channel on arrival, declare the item, and pay taxes and duties. It is recommended you have something (e.g. and invoice) that shows the value of the item, otherwise they will make their own estimate.
In practice, if you wear it, thereβs probably little chance they will notice (though that can vary a lot based on your personal circumstances), but if for any reason they search your belongings and find the box or invoice you will not only need to pay the taxes and duties but possibly a penalty as well.
Note also that it is often quite easy to make the difference between a brand new gold bangle (which will be shiny and unscratched) from one that has actually been worn for a while. Some customs agents can be quite good at detecting those.