Where does Pearl earrings come from?

Pearls are usually from oysters. Most pearls today are cultured pearls, meaning that they are specially done.

What they do is to put an irritation into the oyster shell so that the oyster can make a pearl. A pearl is really just kind of a "tumor" thingie. The oyster can't get rid of some irritants like sand or grit, so it will deposit something called nacre over the thing that is bugging it. Over time, this will become a real pearl and it's size depends on how long the oyster has to coat the thing. The reason it's called a cultured pearl is that man will put the "dirt" in the pearl rather than it happening naturally.

So after the pearl has been taken from the oyster, jewelers will mount it on an earring mounting. These mountings are usually precious metal, and the price of the earrings depends on the quality of the pearl, the shape of the pearl, and the quality of the earring mounting.