Between 1765 and 1770, a 70 foot New England ship carrying a large cargo of British ceramics sank in what is now Biscayne National Park in Florida. Conservator Cait Shaffer has been treating several coral covered ceramic figurines from the ship, nicknamed the English China wreck, using chemical cleaning techniques as well as a sonic descaler (the same instrument your dentist may use to clean your teeth). Cait has made a fantastic time-lapse photography presentation showing the removal of the encrustations from one of the figurines, and you can see it by clicking here.
2 of the Biscayne Figurines:
Maryland History by the Object 