Different Types of Pottery Clay

1. Earthenware clay: This type of clay has a high iron content and is typically red or orange in color. It is porous and not very strong, but is easy to work with and is often used for making decorative pottery.

2. Stoneware clay: This type of clay has a lower iron content and is usually gray or brown in color. It is stronger and less porous than earthenware clay, making it suitable for functional pottery such as dishes and cookware.

3. Porcelain clay: This type of clay is made from kaolin and feldspar, and is very white and fine-grained. It is the strongest and most durable of the three types, but also the most difficult to work with. Porcelain pottery is typically used for high-end decorative pieces and figurines.

4. Ball clay: This type of clay is composed mainly of kaolinite and is usually mined in the southern United States. It is often used to make fine porcelain and to mix with other clays to improve their plasticity and strength.

5. Fireclay: Fireclay is a type of clay that can withstand high temperatures without breaking down. It is often used for making kiln furniture, such as bricks and shelves, as well as for making firebrick.

6. Bentonite Clay: Bentonite is a unique clay due to its ability to produce an "electrical charge" when hydrated. Upon contact with fluid, its electrical components change, giving it the ability to "swell" almost like a sponge. This characteristic makes it useful in drilling muds for oil and gas wells and for animal feed.

7. Talc: Talc is a soft mineral that is used as a filler and lubricant in ceramics and pottery. It can also be used to reduce the firing temperature of clay bodies and to improve their plasticity.