What I expected to happen was...:
Hardened clay would be named hardened clay.

What actually happened was...:
It was named "tile.HardenedStained.name" in statistics.

Steps to Reproduce:
1.Go to creative mode and spawn some hardened clay, and a pickaxe. try all colors of clay.
2. Go into survival mode and mine the hardened clay.
3. Press Esc and go into statistics.
4 Scroll down and find hardened clay, notice it's named "tile.HardenedStained.nane"