I know I’ve given you a somewhat blurry photo, but it wouldn’t be the championship edition of NAME THAT FRUIT! otherwise.
In Bai Tu Long Bay there’s floating Pearl Farm with a built-in jewelry store. It’s a little strange browsing jeweler’s cases with a bunch of people in life-jackets. On the way into the store they show you how pearls are cultured and harvested, presumably in an attempt to engender a sense of gratitude / reciprocity from those who are really psyched about it.