Mostly referring to pottery and porcelain recovered from wrecks of sunken ships trading to China.
Ceramics and full cargoes recovered during controlled excavations have greatly improved our knowledge of cultural exchange and historical trade routes as well as being a valuable addition to our knowledge of kilns and chronology of ceramic development.
Shipwreck porcelain is interesting because they offer a possibility to acquire porcelain with a known provenance. Since they also often are possibly to date quite precisely this also makes them interesting as reference pieces for dating other objects, creating a chronology and immensely adding to our understanding of our history. For the last few decades, maritime archaeological excavations besides being great adventures have brought our knowledge of ceramic history to an entirely new level.