Hey! The mr blinky website (https://mrblinky.net/tama/friends/ezgotchi/), if you put in your PC login code and enter what you want, can get you free jewelry and other stuff! YAY!!!!!!
Thought I'd add to this: you can also obtain jewellery via 'Bumping' with another device. If you go to the treasure chest, you'll find that you can't get some of them. Thats because they are online exclusive!