(here and everywhere in the world)is not a good idea unless it is insured and assured that the package is going to be safe.

And I would say a Diamond ring is not a "small" item to be sent over a post/courier service.

What if it gets lost? What if they say in Dubai "we did not get anything here". What if the person who receives calls you and says "the package is empty? What to do? Where to go? Where to complain? How to complain?

Better approach all possibilities in Doha (meaning post office and couriers) and ask them for the "safer" way to have your valuable sent over to UAE.

have you considered asking a friend going to UAE any time soon and send it through him/her/them??

Regards!!