Porcelain keeps the tea warm without being too hot to hold.
Traditionally, Chinese teacups don't have handles, and for a good reason. Historically it was done for convenient transportation, as one could stack them into each other very easily.
It is also believed that the smaller the cup, the more interest you have in the drink, its smell, taste and aftertaste. Don't we all need to slow down and enjoy such things.
These beautiful handmade cups are unique, no two cups are the same.