Slate is a fine-grained, hard rock made up of clay, mica, quartz and other minerals. Because it is durable stone with a low moisture-absorption
rate and a stable surface, slate is extremely well suited for use in billiards. In the United States, slate is located in Vermont, Pennsylvania,
Virginia and Arkansas, and is also present in other countries such as Wales, Spain, China, Korea, Italy and Brazil. Depending upon the mineral
content in any specific area, slate can be found in many colors. While most slate is gray or black, it can also be red, green and purple.
It is important to remember that billiard slate quality is not measured by color or by country of origin, but by one key characteristic: a flat surface.
Source: Brunswick Billiards