Frankly speaking, ceramic tea mug could also be used for coffee drinking.
However, most ceramic coffee mugs are without ceramic lid.
For tea drinking, and for many kinds of tea, there must be a ceramic lid on the ceramic tea mug.
Because when people make tea, the ceramic tea mug needs to maintain at a constant temperature and also needs to keep the tea perfume in the mug.
Then comes the ceramic lid.
For ceramic tea mug, there are many kinds such as tone-ware tea mug, porcelain tea mug, decal printing ceramic tea mug, color glazed ceramic tea mug ect.