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, stone, metal, baked clay, or even glass. They are generally fixed in place in an array to cover roofs, floors, walls, edges, or o ...

, usually formed in the shape of a

square In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90-degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length adj ...

, 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, and covering a surface. Mosaics are often used as floor and wall decoration, and were particularly pop ...

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

Historical tesserae

The oldest known tesserae date to the 3rd millennium BC, discovered in the ancient city of

Shahdad Shahdad ( fa, شهداد, also Romanized as Shahdād; formerly, Khabīs) is a city and capital of Shahdad District, in Kerman County, Kerman Province, Iran. At the 2006 census, its population was 4,097, in 1,010 families. District Shahdad is t ...

Kerman Kerman ( fa, كرمان, Kermân ; also romanization of Persian, romanized as Kermun and Karmana), known in ancient times as the satrapy of Carmania, is the capital city of Kerman Province, Iran. At the 2011 census, its population was 821,394, in ...

province,

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

. In early antiquity,

s were formed from naturally formed colored

pebble A pebble is a clast of rock with a particle size of based on the Udden-Wentworth scale of sedimentology. Pebbles are generally considered larger than granules ( in diameter) and smaller than cobbles ( in diameter). A rock made predominant ...

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

Hellenistic In Classical antiquity, the Hellenistic period covers the time in Mediterranean history after Classical Greece, between the death of Alexander the Great in 323 BC and the emergence of the Roman Empire, as signified by the Battle of Actium in ...

- Greek mosaics. For instance, a large body of surviving material from the Hellenistic period can be found in the

mosaics of Delos The mosaics of Delos are a significant body of ancient Greek mosaic art. Most of the surviving mosaics from Delos, Greece, an island in the Cyclades, date to the last half of the 2nd century BC and early 1st century BC, during the Hellenistic ...

, Greece, dating to the late 2nd century BC.

Ancient Roman In modern historiography, ancient Rome refers to Roman civilisation from the founding of the city of Rome in the 8th century BC to the collapse of the Western Roman Empire in the 5th century AD. It encompasses the Roman Kingdom (753–509 BC ...

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

Pompeii Pompeii (, ) was an ancient city located in what is now the ''comune'' of Pompei near Naples in the Campania region of Italy. Pompeii, along with Herculaneum and many villas in the surrounding area (e.g. at Boscoreale, Stabiae), was buried ...

Marble Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or Dolomite (mineral), dolomite. Marble is typically not Foliation (geology), foliated (layered), although there are exceptions. In geology, the ...

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

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 referred to as the Eastern Roman Empire or Byzantium, was the continuation of the Roman Empire primarily in its eastern provinces during Late Antiquity and the Middle Ages, when its capital city was Constantinopl ...

s used tesserae with

gold leaf Gold leaf is gold that has been hammered into thin sheets (usually around 0.1 µm thick) by goldbeating and is often used for gilding. Gold leaf is available in a wide variety of karats and shades. The most commonly used gold is 22-kara ...

, 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.

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 with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile met ...

and silver

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

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

Mirror

Mirror A mirror or looking glass is an object that Reflection (physics), reflects an image. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the ...

fragments are available as offcuts from glass cutting shops.

Stained glass

Opaque

stained glass Stained glass is coloured glass as a material or works created from it. Throughout its thousand-year history, the term has been applied almost exclusively to the windows of churches and other significant religious buildings. Although tradition ...

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 ''Trencadís'' (), also known as pique assiette, broken tile mosaics, bits and pieces, memoryware, and shardware, is a type of mosaic made from cemented-together tile shards and broken chinaware. Glazed china tends to be preferred, and glass is so ...

or pique assiette technique.

References

External links

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