Concept:
Porcelain is a fine and strong ceramic material produced by firing specially prepared clay materials at very high temperatures.
Step 1:
Porcelain is known for its hardness, whiteness, smooth texture, and translucent appearance.
Step 2:
Traditional hard-paste porcelain is mainly prepared using two important materials:
• Kaolin (white China clay)
• Petuntse (China stone)
Step 3:
China clay provides plasticity and whiteness to porcelain and helps the material maintain its shape during firing.
Step 4:
China stone or Petuntse acts as a flux during heating and gives porcelain its glass-like hardness and smooth finish.
Step 5:
The combination of white China clay and China stone accurately describes the traditional composition of porcelain.
\[
\boxed{\text{(1) white China clay and China stone (Petuntse)}}
\]