I love these "pearls"!  These are Shell Pearls in a unique "baroque" shape, which means they are a little wonky and misshapen.  Many natural pearls in history had a "baroque" shape since perfect natural teardrop pearls are extremely rare.  

These are especially good for earlier costuming (like the Elizabethan and Restoration eras)!

The pearl drops are about 16mm long so these are a nice impactful size. 

Note that each of these stones is unique, so note there may be a small amount of variation in the earrings you receive.