What is porcelain? It is an insulator or Conductor?

Porcelain is a ceramic material made by heating materials, generally including material like kaolin (a fine soft white clay, also called china clay), in a furnace to temperatures between 1,200 and 1,400 °C (2,200 and 2,600 °F). 

The term porcelain is derived from porcellana, which was used by Marco Polo to describe the pottery he saw in China. 

As it is made of kaolin (clay) it is an insulator.