A tessera (plural: tesserae, diminutive ''tessella'') is an individual

tile Tiles are usually thin, square or rectangular coverings manufactured from hard-wearing material such as ceramic, Rock (geology), stone, metal, baked clay, or even glass. They are generally fixed in place in an array to cover roofs, floors, wal ...

, usually formed in the shape of a

square In geometry, a square is a regular polygon, regular quadrilateral. It has four straight sides of equal length and four equal angles. Squares are special cases of rectangles, which have four equal angles, and of rhombuses, which have four equal si ...

, used in creating a

mosaic A mosaic () is a pattern or image made of small regular or irregular pieces of colored stone, glass or ceramic, held in place by plaster/Mortar (masonry), mortar, and covering a surface. Mosaics are often used as floor and wall decoration, and ...

. It is also known as an abaciscus or abaculus. Chapelle Palatine

Historical tesserae

In early antiquity,

s were formed from naturally formed colored

pebble A pebble is a clastic rocks, clast of rock (geology), rock with a grain size, particle size of based on the Particle size (grain size), Udden-Wentworth scale of sedimentology. Pebbles are generally considered larger than Granule (geology), gra ...

s. By roughly 200 BC cut stone tesserae were being used in

Hellenistic In classical antiquity, the Hellenistic period covers the time in Greek history after Classical Greece, between the death of Alexander the Great in 323 BC and the death of Cleopatra VII in 30 BC, which was followed by the ascendancy of the R ...

- Greek mosaics. For instance, a large body of surviving material from the Hellenistic period can be found in the mosaics of Delos, Greece, dating to the late 2nd century BC.

Ancient Roman In modern historiography, ancient Rome is the Roman people, Roman civilisation from the founding of Rome, founding of the Italian city of Rome in the 8th century BC to the Fall of the Western Roman Empire, collapse of the Western Roman Em ...

decorative mosaic panels and floor mosaics were also produced during the 2nd century BC, particularly at sites such as

Antioch Antioch on the Orontes (; , ) "Antioch on Daphne"; or "Antioch the Great"; ; ; ; ; ; ; . was a Hellenistic Greek city founded by Seleucus I Nicator in 300 BC. One of the most important Greek cities of the Hellenistic period, it served as ...

and

Pompeii Pompeii ( ; ) was a city in what is now the municipality of Pompei, near Naples, in the Campania region of Italy. Along with Herculaneum, Stabiae, and Villa Boscoreale, many surrounding villas, the city was buried under of volcanic ash and p ...

Marble Marble is a metamorphic rock consisting of carbonate minerals (most commonly calcite (CaCO3) or Dolomite (mineral), dolomite (CaMg(CO3)2) that have recrystallized under the influence of heat and pressure. It has a crystalline texture, and is ty ...

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

were cut into small cubes and arranged into representational designs and geometric patterns. Later, tesserae were made from colored glass, or clear glass backed with metal foils. The

Byzantine The Byzantine Empire, also known as the Eastern Roman Empire, was the continuation of the Roman Empire centred on Constantinople during late antiquity and the Middle Ages. Having survived the events that caused the fall of the Western Roman E ...

s used tesserae with gold leaf, in which case the glass pieces were flatter, with two glass pieces sandwiching the gold. This produced a golden reflection emanating from in between the tesserae as well as their front, causing a far richer and more luminous effect than even plain gold leaf would create.

Contemporary tesserae

Wooden block with hammer and cutting board for cutting mosaic tiles

Vitreous glass

These are manufactured glass tiles made to a uniform shape and size. They are made by molten glass being poured into trays and fired. An imprint of grooves is made on their underside for help with adhesion to cement when fixing.

Iridised, marbled, & metallic tesserae

Iridised (with a reflective quality), marbled (featuring contrasting and complementary colors), metallic (semi-transparent with gold or bronze veins), and millefiori (round handmade Murano tesserae with intricate patterns) tesserae are also widely used.

Ceramic tesserae

These are the cheapest range of bought materials and can be glazed or unglazed. The glazed ceramic tiles have the color painted onto the top of the clay and then fired to a high temperature in a kiln. The unglazed or body glazed version has the color mixed into the wet clay so the color runs through them. They vary in size.

Smalti

This is the classic mosaic material. It is opaque glass fired in large slabs in a kiln and then hand cut into small cubes with a hammer and hardy chisel. Their irregular finish makes them a wonderful reflector of light and this material is best used working straight into cement. It is produced in Venice and sold by colour and weight.

Gold smalti

This tile is made with

gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

and silver

leaf A leaf (: leaves) is a principal appendage of the plant stem, stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leav ...

sandwiched between two layers of glass and fired twice in the kiln to embed in the metal.

Mirror

Mirror A mirror, also known as a looking glass, is an object that Reflection (physics), reflects an image. Light that bounces off a mirror forms an image of whatever is in front of it, which is then focused through the lens of the eye or a camera ...

fragments are available as offcuts from glass cutting shops.

Stained glass

Opaque

stained glass Stained glass refers to coloured glass as a material or art and architectural works created from it. Although it is traditionally made in flat panels and used as windows, the creations of modern stained glass artists also include three-dimensio ...

comes as large sheets that can be cut into smaller sections with a glasscutter.

Household ceramic tiles and china

Various household objects, including pottery shards, can be used, especially in trencadís or pique assiette technique.

References

External links

* {{Authority control Mosaic Visual arts materials Stone (material)