The term slate is often used to describe any rock that can be easily split into thin sheets, principally for roofing purposes. True slate is defined by the presence of a ‘slaty’ cleavage; this allows the slate to be split at almost any point through the stone parallel to the cleavage plane.

The major UK sources of slate, with their distinctive colours, are the Lake District blue/grey, light green, olive green and silver grey, North Wales blue, grey, blue-black and red, and Cornwall - grey.

Slate is easily split (“riven”) into thin sections, giving a natural finish. Other finishes include sawn, sanded, fine rubbed, flame textured, bush hammered and water jet.

It is popular for a wide variety of uses such as roofing, flooring, and flagging because of its durability and attractive appearance.