I did this in DTD. There is a kiosk in DTD. You can purchase right out of their display case or have something made after you crack an oyster open.
I think it was $25 to open an oyster, welcome it into the world and then choose how you would like it set. I opted for a pendant necklace the first time. The pearls can be accomanied by other stones- like diamonds, they are pulled out and offered when selecting your setting.
On another trip I skipped the oyster opening and selected a pair of earrings with diamonds attached out of the case.
There are colored- like pink and black pearls, as well as your white pearls. These are top quality mikimoto pearls.