Jewellery items for a boy

[SOT3]

I have bought a type of jewellery box (requested) for a 7 year old boy, and would like to put some items inside it before giving.

I have looked in the high street shops for boy's jewellery but have not found any, does anyone know of places I could buy some please?

Shark tooth necklace, cheap and easy to find. My grandson chose a bug necklace from his great grandmother after she died. He will wear it too. Also 7.