Agateware - or "Swirlware" as it is often called in the US Mid West, is pottery made with multiple colors of clay. So unlike glazing the colors comes from the clay - not an added layer of color.

With the Agateware technique very unique pottery can be created. It stand out, feels and look very different to all other ceramics.

I most often create Agateware (Swirlware) pottery from the same kind of light white clay were some of it has been mixed with colorants. 

Sometimes I mix different kinds of clay - such as dark stoneware and white porcelain. However that is a very tricky process with a high fail rate as the different kinds of clay do not dry and shrink equally. But when it's successful it's quite outstanding. 

After mixing the different colors of clay they are stacked on top of each other and very gently thrown to the final pot shape on the potters wheel. I have to be very careful - if I throw too long the colors end up blending too much into each other. 

I like how Agateware stand out in sort of a mysterious way. The colored clay makes they appear somehow deeper - in contrast to color glazed pots.