Thank you for contacting Mearto with your appraisal inquiry.

It is a beautiful heartshaped locket. Such vintage jewellery are being offered at auction on a regular basis.
The locket is probably made of silver with gilding on the interior. This is how most of these lockets from the early 1900s were made. Without any silvermarks it is hard to tell the origin of the locket. I can see that it says gold shell on the interior however that does not indicate either origin or age. The exterior decoration was typical of the late 1800s and early 1900s as well as the heartshape.
This particular type of jewellery is often seen in antique markets and they are quite popular however it is not a rare item which is indicated in the price. This particular locket appears to be in good condition, the heart shape adds to the charm and the beautiful engraved decoration on the outside is also a nice feature.
I would suggest polishing it very gently with a soft cloth - hopefully this does the trick.
As for the price - I think you paid a fair price for it. If you sold it you would probably make a small profit.

The estimate provided is for a well-advertised specialised online jewellery auction, where I believe the locket has the best chance of realising its fullest potential. However, there is no measurement for the sentimental value you might attach to the locket. Retail "asking prices" can be higher and vary.

Please let me know if you have any additional questions. I’m happy to help.
Thank you