|Required for||Units: None|
Porcelain, unlike most other resources, doesn't appear on the map, but is instead made through the exceptional skills of the artisans in a mercantile city-state. Thus, it is available only if you ally yourself with this city-state. You won't get this resource if you conquer or buy the city-state - the artisans will simply disperse and refuse to work for you!
Note that only one of the two special resources is available in each mercantile city-state: either Porcelain or Jewelry. Note also that they are available alongside normal luxuries that the city-state will produce from the surrounding land.
First created in China nearly 3,000 years ago, porcelain is a type of ceramic material formed by heating clay to create semi-translucent vessels of varying shapes and sizes. Artists and craftsmen spent centuries developing the techniques that allowed for control of both the aesthetic qualities as well as the physical strength and usability of porcelain objects. Having originated in China, porcelain dinnerware was often referred to simply as "China" during the height of its popularity in Europe.