Porcelain Pillows

Porcelain pillows were mainly common in the Song dynasty (960 - 1279), as is shown by plenty of shapes and types.
You might suspect that they were used in tombs for the departed,  as their hardness seemingly makes them look too hard to be comfortable, but they were actually widely used by the living population.
It might well be that something was placed on top of them at times, but in the heat of summer they were ideal.

Shown below are two examples of porcelain pillows made at Cizhou kiln, in the Song dynasty.

Porcelain pillow examples

Fan shaped porcelain pillow with phoenix decoration, Song dynasty

Ruyi-shape pillow

I tested this! As a result I am intent of obtaining or having made a copy of it.
Like many others I have always doubted that these hard pillows would be suitable for living humans. When I obtained one I jumped to the opportunity to verify this. To my surprise its shape was not only highly ergonomic but probably the most comfortable pillow used in a decade (including the modern ones). The porcelain was cool to the touch, much more so than any other pillow materials, and its slightly rounded shape is perfect for sleeping on the side. I spent many an hour sleeping on this without ever getting a headache or sore head.
(This is just another proof of the wisdom of those ancient people of the Song dynasty.)

Song dynasty ceramics