Maiolica/Majolica — Originally earthenware with white tin glaze, painted in bright colours and produced in Italy and Spain. The term 'majolica' was applied in the 19th century to relief tiles with colourful opaque glazes.
Manganese — A metal, the oxide of which produces a purple glaze much used on Dutch and English tin-glazed tiles.
MARBLE — A metamorphic rock whose crystalline structure is easily worked. Marble, therefore, is a popular tiling and mosaic material.
MARBLE DUST — A fine-grained or coarse-grained dust of crushed marble used as a dye or an inert material in preparing mortars.
MDF — Medium-density fibreboard, created out of densely compressed wood fibre, which is very easy to cut. It is not water-resistant and as such is not a suitable base for tiling.
Meander — a decorative border and a pattern consisting of lines turning in and out at right angles and crossing one another. Also known as Greek Lines, Greek Fret or Greek Key.
MICROMOSAICS — Speical, extremely laborious, form of mosaics created from thousands of minute tesserae cut from glass threads. There can be as many as 1,400 tesserae per square inch of micromosaic.
MORTAR — A generic term for a mix of binder, aggregate and water.
MOSAIC HAMMER — A steel or iron hammer with two cutting edges made of widia. Together with the hardie, it is used to cut tesserae.
MOSAIC PAPER — White paper specially produced for mosaics. It is characterized by a rough side on which tesserae are pasted and a shiny side on which the instructions for the mosaic worker are placed.
MOVEMENT / EXPANSION JOINT — Gap in the tile or stone surface to absorb the movement in the floor or wall from background shrinkage or expansion, thus preventing tiles from cracking. The requirements to movement joints are laid out by British Standards (BSI) 5385.
Mudéjar — A term in design history which refers to a style of architecture and design that is a mixture of Islamic and Gothic styles. The style was particularly prevalent in Spain between the 13th and 15th centuries when Muslim craftsmen worked for Christian masters.
Muffle kiln — A relatively low-temperature kiln with an interior chamber totally enclosed and separated from the main kiln which shields the ware from the direct flames and combustion gases.
muriatic acid / HYDROCHLORIC ACID — A powerful acid, an aqueous solution of hydrogen chloride, used as a cleaning agent to remove unwanted cement and cement–based products from the surface of a tile or a mosaic.
Musearius — also musivarius, in ancient Rome, craftsman who specialised in (opus) museum or musivum, that is wall mosaic.
Museum — also musivum, literally 'pertaining to the Muses', used to signify wall mosaic.
