The physical materials architecture is built from, treated as material subjects in their own right: stone, timber, fired brick, concrete, structural steel, glass, adobe and other traditional and modern building materials, each carried with its composition, structural and aesthetic properties, and the era or region where its use became significant. Belongs here: a named building material or material class considered for its own composition and properties, such as reinforced concrete, ashlar stone, timber framing or float glass. Does not belong here: a structural or design element built from a material, such as the arch, vault, dome or column, which is Elements and Materials' subject, a specific named building constructed from a material, which is Buildings and Structures' subject, or a style or movement defined partly by its characteristic use of a material, which is Styles and Movements' subject.