Anthracite is considered the best quality variety of coal.

1. Anthracite: It is a hard, black, and shiny coal with high carbon content and low moisture and volatile matter. It has the highest energy content among all coal types and burns clean, producing less smoke and fewer emissions. It is commonly used for domestic heating and industrial purposes.

2. Bituminous: It is a soft coal with moderate carbon content and higher moisture and volatile matter compared to anthracite. It is widely used for electricity generation and in industrial processes.

3. Lignite: It is the lowest rank of coal, characterized by high moisture and volatile matter content. Lignite has a lower energy content and is commonly used for electricity generation in power plants.

4. Peat: It is the lowest rank of coal and is not a true coal but rather partially decomposed plant material. Peat has high moisture content, low heat content, and is not widely used as a fuel.

In summary, while all coal types have their uses, anthracite is considered the best quality due to its high carbon content and energy efficiency.