There is a shop in the indoor part of the gold souk who sells some nice pearls - different colours. Go in and then turn left around the corner, he is about third on the left. He has some nice gems as well. There are other shops and you can haggle on prices and settings etc. They are mostly `man-made' factory pearls. The prices aren't bad as a result.
There is a pearl diver's shop in Souq Waqif. Its the 1st shop to your left as you start entering the main buzz street.
He has pearls in different sizes with varied price ranges. But do know that he gets his pearls from China (no more diving) :D Well you know almost all pearls are cultured. So you can choose if you want Japanese, Chinese, Tahitian or ...
Last year at the Watch & Jewelry exhibition, I saw a pearl necklace which was stunningly beautiful. And I did convince my hubby to by me while we were admiring it from outside.
And then when I asked the sales guy, I froze with the figure he quoted - 5,00,000 QR...
:D we laughed and left coz my hubby could get 2 cars for the price of one pearl necklace !