SAH Archipedia uses terms from the Getty Art and Architecture Thesaurus (AAT) to categorize and classify metadata for the entries in the database. For more information on the Getty AAT, click here

Click on the icon to view the definition of the selected term.

diatomaceous earth

An soft, whitish, absorbent powder derived from the siliceous skeletons of microscopic water plants called diatoms, composed of 88% silica. It is used as a poultice, a desiccating insecticide, a decolorizer and filtration aid for purifying oils, fats, and waxes, an inert pigment, a filler in paper, paint, brick, floor tiles, ceramics, linoleum, plastic, soap, and detergent, an insulation for boilers and blast furnaces, as sound insulation, and as a very mild abrasive in metal polishes and toothpaste. It reduces gloss, acts as a suspending agent, increases viscosity, and absorbs dyes well, thus is used as a base for lake colors.

dimension lumber

Lumber cut to a particular size and stocked for the building industry; usually 2 to 5 inches thick and 5 to 12 inches wide.

dimension stone

Stone finished to a specific size and weight and squared to specific dimensions and thickness.


A hard, coarse-grain, black-and-white speckled, granite-like rock composed of plagioclase feldspar mixed with hornblende, biotite, and augite, sometimes with small amounts of orthoclase or quartz. Diorite was valued by the Egyptians and Sumerians for statuary and is presently used in building construction.

direct metal sculpture

Sculpture that is constructed of metal using such processes as welding, hammering, and soldering as opposed to casting.


Facilities where the distilling and blending of spirits is carried on, including processes by which evaporation of water and subsequent condensation of the alcoholic beverage is achieved.

dogwood (wood)

Wood of trees belonging to the genus Cornus. Although dogwoods are primarily grown as an ornamental trees, their fine-grained wood is hard and heavy, ranging in color from yellow to pinkish-brown, and has been used for small ornamental items and utilitarian objects such as skate rollers, golf club heads, pulleys, hammer handles, and in the textile industry for shuttles and spindles.

dolomite (mineral)

A common rock-forming mineral.

Doric order

Refers to the architectural order characterized by columns generally without bases, relatively simple capitals, and a frieze composed of alternating triglyphs and metopes.

double-hung windows

Windows having two vertically sliding sashes, each closing a different part of the window; the weight of each sash is counter-balanced for ease of opening and closing.

Douglas fir (wood)

Wood from trees of the genus Pseudotsuga.

drain tile

Ceramic tile, usually in short-length sections, used for constructing water drains.

dressed lumber

Lumber machined and surfaced at a mill.

dressed stone

Dimension stone with a smooth exposed face.


Wood floating on water, or that has been cast ashore.

dry mortar

In masonry, mortar which contains enough moisture to cause it to set properly but is not wet enough to cause it to be sticky.

dry walls (masonry)

Masonry walls constructed without mortar.

Dryopteris (genus)

Genus containing about 250 species of fern.


A compound -- generally a complex organic material that dissolves or is suspended in a liquid -- that absorbs into and colors another material. Distinguished from a pigment, which is insoluble in the vehicle, but instead is held in a suspension.


Blasting explosive made with a mixture of nitroglycerin and other inert absorptive substance. Detonated by heat or percussion.

earth (soil)

Refers to soil in the context of building materials.

earth construction

Process or technique of constructing architecture or other works using earth, either by digging into the earth or by creating building materials from earth. If the earth has been fired, such as with bricks, prefer "masonry construction."

earthen architecture

Buildings and other architectural structures constructed wholly or primarily of earth. For engineering works, such as trenches, created in the earth, use "earthworks (engineering works)." For structures built on a hillside rather than into it, use "hillside architecture." For structures built under the surface of the ground, but not made primarily of earth, use "underground structures."

eastern white pine (wood)

Wood from the Pinus strobus, native to eastern North America.

ebony (wood)

A hard, heavy, durable heartwood wood yielded by various trees of the genus Diospyros in tropical Asia and Africa, valued for its dense, smooth-grain from the earliest times; was imported to Egypt from Nubia and the Sudan. It is extremely durable, resistant to rotting, fungi and powder post beetles, but difficult to work and carve. It has been used for decorative items, inlay work, black piano keys, musical instruments, and tool handles. Several other dark, heavy woods from unrelated species are also called ebony because of their color, including cocuswood, coffeewood, blue ebony, and African blackwood.

emerald (mineral)

A brilliant grass-green variety of beryl, highly prized as a gemstone. The name comes indirectly from the Greek "smaragdos," referring to a number of stones having little in common except a green color. The emerald in the the Bible was probably a garnet. However, ancient societies did also value the genuine emerald, which came from Upper Egypt as early as 2000 BCE. Greek emerald miners worked for Alexander the Great and Cleopatra. The physical properties of emerald are essentially the same as those of beryl, with only moderate light refractive and dispersive powers, meaning that cut stones display little brilliancy or fire. The gems are instead valued for their magnificent color, which is probably caused by small amounts of chromium. The stone loses colour when strongly heated. Synthetic emerald was successfully produced in the 1930s, and today is produced by a either a molten-flux process or a hydrothermal method crystal growing process. Synthetic crystals appear very similar to natural emerald crystals.

enamel (fused coating)

A semi-transparent or opaque vitreous, porcelain-like coating applied by fusion to metal, glass, or ceramic, having a glossy appearance after hardening. Enamel is typically made from powdered fusible glasses (e.g., quartz, feldspar, clay, soda, and borax) and opaque colorants (e.g., cobalt blue, tin oxide) mixed with oil or water, then painted or sprayed on the object and fired up to 800 C. Enamel is used to protect a surface, to decorate objects in various colors and patterns, to form a surface for encaustic painting, and for other purposes.

encaustic tile

Ceramic tile having a decorative pattern that is not applied by glaze, but by using multiple color clays.

engineering brick

Brick having the nominal dimensions 3 1/5 in. by 4 in. by 8 in. (8.13 cm by 10.16 cm by 20.36 cm).

English (language)

West Germanic language of the Indo-European language family that is closely related to Frisian, German, and Dutch (in Belgium called Flemish) languages. It is spoken in England and also used in many varieties throughout the world.

English bond (masonry technique)

Technique of bond in which alternating courses of all headers and all stretchers are laid, with the headers centered on the stretchers and on the joints between stretchers.

English oak (wood)

Wood of the species Quercus robur, having a coarse but straight grain that is usually a rich brown color. Flat sawn timber has a distinctive figuring while radial cut lumber has silver grain lines. The wood has a high gallic acid content that will corrode iron and other contacting metals. English oak is widely used in furniture, paneling, railway sleepers, cabinet, musical instruments, and ship building.

English walnut (wood)

Wood of the species Juglans regia, native to the Himalayas, Iran, Lebanon, Asia Minor, and Greece. It was introduced into Britain in the mid-15th century. It has a uniform, deep brown color with a medium texture and a close, straight grain. It varies considerably in color the sapwood being pale straw with grayish-brown heartwood with infiltrations of coloring producing a darker-colored streaky appearance. It is strong but easy to work and polishes to a high gloss. It is used for furniture, veneers, cabinets, paneling, gun stocks. Its burls are especially prized in the furniture trade. For the darker wood from the species Junglans nigra found in the eastern United States, use "black walnut."

epoxy resin

Type of synthetic resin used to produce adhesive that sets by chemical reaction, rather than through loss of solvent and coalescence.

Ericales (order)

Large, diverse order of dicotyledons (flowering plant having two cotyledons or seed-lobes), such as tea, persimmon, blueberry, Brazil nut, and azalea. In some older classifications, families in this order were distributed in various separate orders, such as the Ebenales order.


Continuous, curly, fine wood shavings employed as stuffing for furniture, packing material for breakable articles, and other purposes.

exterior insulation and finish system

Lightweight and economical cladding system for buildings composed of insulation and wet applied finish.

extrusive rock

Igneous rock solidified on or near the surface after being ejected explosively or extruded as lava, as contrasted with intrusive rock; characteristically finely crystalline or glassy.

face brick

The better quality of brick such as is used on exposed parts of a building, especially those parts which are prominent in view.

Fagus (genus)

Genus having ten species of deciduous, smooth-barked trees native to temperate regions of the northern hemisphere. Trees have pale reddish-brown, close-grained wood valued for flooring, cabinetry, furniture, panel painting, and other uses. Beech nuts provide forage for game animals and yield an edible oil.

Fagus grandifolia (species)

Species of large deciduous tree up to 35 meters in height, native to eastern North America, from Nova Scotia to Texas, having a pale reddish-brown timber that is hard, tough, fine-grained, and used for furniture and other purposes. The bark is smooth and gray. Leaves are simple with veins and toothed edges. Fruit comprises a large husk containing 2 shiny brown edible nuts. The wood is acidic, pinkish brown in color with dark brown rays.

Fagus sylvatica (species)

Species of large, long-lived beech tree found throughout England and Eurasia; it passes 30-40 years in the juvenile stage, during which time there is rapid growth but no flowering. It can grow to 49 m (160 feet) in height; it has a smooth gray bark and a hard, heavy wood. European beech trees are often grown in large hedgerows.

faience (composite material)

A composite material consisting of a body of sintered quartz coupled with an alkaline glaze surface, and used for decorating beads, amulets, figurines, and other small objects. It was invented in Mesopotamia or Iran ca. 4500 BCE, and produced through the mid-7th century CE.

faience tile

Glazed or unglazed ceramic tile which shows characteristic variations in the face, edges, and glaze that give a handcrafted, non-mechanical, decorative effect.


Semicircular windows over doors or other openings with radiating bars giving the appearance of an open fan.


Refers to all of the animals or animal life of a particular area or time period.

Favrile glass (TM)

Trademark name for a type of glass developed by Tiffany and Company with an iridescent surface simulating that of excavated ancient Roman glass; this effect was produced by spraying the surface of the glass while hot with metallic salts.


General name for a large group of aluminum silicate minerals, usually white or flesh-red in color, occurring in crystals or in crystalline masses. Feldspars are divided into three primary groups: potassium aluminum silicates (orthoclase, microcline), sodium aluminum silicates (albite, anorthoclase), and calcium aluminum silicates (anorthite). A few of the feldspars are found as gemstones such as moonstone, sunstone, and Amazon stone, but most are found in mineral structures, such as granite and diorite. They are used in the production of clays, ceramics, glass, concrete, abrasives, for cleaning, as a flux in ceramics, glazes, and glass, in fertilizer, and in granular roofing material.

ferruginous sandstone

A soft sandstone containing red iron oxide, having a reddish-brown color.


A rigid composite board of pressed cellulose, generally composed of wood chips or plant fibers, such as grass, reed, straw, bagasse, jute, flax, hemp, or recycled waste materials such as sawdust, bark, oat hulls, spent hops, newspaper and peanut shells. The fibers are compressed and bonded with heat and pressure. Many fiberboards are held together by the interlocking fibers and natural adhesives (wet process); other fiberboards have additional adhesive components such as urea formaldehyde resin, water glass, dextrin, asphalt, rosin, paraffin wax, plaster, and/or clay.


Generic term for glass fibers, glass fabrics, and resins reinforced with glass fibers; fiberglass is strong, lightweight, nonflammable, with a high tensile strength. The material dates to 1893, when spun glass fibers were made into fabric by Edward D. Libbey and exhibited at the Columbian Exhibition in Chicago. Owen-Corning developed several processes for making fine, continuous glass fibers in the 1930s, which were sold under the trademark of ‘Fiberglas.’ Over time, the term 'fiberglass' became generally used for all glass fiber products.


Concrete containing fibers of such materials as glass, asbestos, wood, steel and plastic in order to reduce weight and increase tensile strength.

field turf
No description is available for this term.


Loose stone found on the ground or in the soil.

figured glass

Generally, glass used in architecture that is cut, embossed, sandblasted, or otherwise embellished.

filbert (wood)

Soft reddish white wood from any of 15 species of the genus Corylus in the birch family. The wood is used generally for small objects such as handles.

filler (inert additive)

An inert powder added to a base material such as a paint, pigment, adhesive, plastic, paper, fabric, wax, or concrete. Fillers may serve multiple purposes such as: extend a matrix, dilute a color, decrease cost, provide bulk, increase strength, improve working properties or generally enhance performance. Examples of materials that are used as fillers are acrylic, calcium carbonate, barium sulfate, clay, diatomaceous earth, glass fibers, glass spheres, gypsum, sand, starch, talc, titanium dioxide.

fir (wood)

Wood of the tree from the genus Abies, although other coniferous evergreen trees are commonly called firs. Timber is typically inferior to that of spruce or pine, but it is used for lumber and pulpwood.

fire brick

Bricks made of refractory ceramic material which will resist high temperatures; used to line furnaces, fireplaces, and chimneys.

fireclay (clay)

Clay capable of withstanding very high termperatures without fusing or softening; used especially for firebrick and crucibles.

fired brick

A frequently used building brick, composed of clays or shales (and sometimes other materials), which has been fired to hardness in a kiln.

fish scale shingle
No description is available for this term.

fitch (hair)

Fur from a European polecat, dark in color. It is used in the fur trade. It is also used in paint brushes, valued for its elasticity.

fixed windows

Windows or portions of window units that are designed not to open.

No description is available for this term.


Refers to large flat sections of slate used for paving and also bluestone cut for this purpose.


Motifs of a conventionalized depiction of flames, usually wavy, peaked forms.

flax (fiber)

Fiber derived from the bast or skin of the stem of the species Linum usitatissimum. Soft, flexible fibers are produced by retting the stem of the flax plant, then washing and cleaning the fibers. Flax fibers of thinner and longer than cotton, but the fiber tube has thicker walls resulting in a stronger thread. Additionally, flax fibers are used for linen fabric, thread for making shoes and bookbinding, fish line, and twine. Waste flax fibers are used in banknotes, cigarette covers, and writing and drawing paper.

Flemish bond (masonry technique)

Technique of bond in which headers and stretchers alternate horizontally and vertically, each header being centered with regard to the stretcher above and below.

Flemish brick

Hard, yellowish paving brick.

flint (rock)

The dark gray or black variety of chert.

float glass

Sheet glass made by floating a ribbon of hot glass on a bath of heated liquid, usually molten tin. The process was developed in 1959 by Pilkington Brothers and is now the world's principal method of manufacturing good quality sheet glass which is clear, flat, with parallel and fire polished sides.

floor brick

Smooth, dense brick which is highly resistant to abrasion; used for finished floor surfaces.

floor tile

Tile used as finish flooring.

flora (plants)

All of the plants or plant life of a particular region or time period.

flower (plant material)

Material comprising flowers, which are the reproductive portion of any plant in the division Magnoliophyta (Angiospermae).

fluorescent lighting

Lighting by fluorescent lamps. Lighting by fluorescent lamps.

fly ash

Finely divided particulate matter resulting from the burning of pulverized coal or wood, often emitted as an airborne pollutant at power and manufacturing plants. Current practice in the United States is to trap and recover fly ash; used as a filler in brick and concrete.

foam (material form)

A gas-liquid continuum in which bubbles of gas are contained in a much smaller volume of liquid which is expanded to form bubble walls.

foamed concrete

A very light, cellular concrete made by adding a prepared foam or by generating gas within the unhardened mixture.

folded plate structures

Structural systems based on one-way plates given additional stiffness by folding into a series of long, narrow planes, the typical sections resembling a series of interconnected Ws or splay-sided Us.

forests (cultural landscapes)

Historically, refers to wilderness areas outside the scope of common law but within the legislation of kings and reserved for royal activities; more recently, used to designate extensive wooded areas, whether maintained for the production of timber or unmanaged and preserving a wilderness of dense growth and wild animal habitats. For forests in the context of a plant community rather than as a cultural landscape, use "forests (plant communities)."

forgings (metal pieces)

Use generally for any metal pieces worked to a predetermined shape by one or more of such processes as hammering, pressing, rolling, or upset forging. Examples of forgings are machine parts.

Formica (TM)

Plastic laminate made by bonding layers of materials such as canvas, glass, paper, or linen with thermosetting resins. May be used to refer to the trademarked product and to similar materials.

fossil fuel

Combustible, carbonaceous material such as coal, petroleum, natural gas, and oil shales that are formed through the decay of remains of organisms during the geological past.

fossiliferous limestone

Limestone that contains fossils.


Remains, impressions, or traces of humans, animals, or plants of past geological ages that have been preserved in the earth's crust. The complex of data recorded in fossils worldwide--known as the fossil record--is the primary source of information about the history of life on Earth. Only a small fraction of ancient organisms are preserved as fossils, and usually only organisms that have a solid and resistant skeleton are readily preserved.

found objects

Objects, natural or human-made, unaltered or only slightly altered, presented by an artist as works of art in themselves or used as parts of works of art.

foundation stones (wall components)

Refers to any supporting stones in the foundation of a structure, often of a rougher or different texture than the stones used in the upper part of the building.


Structures with apertures designed to allow water to spout or flow periodically or continuously, as for amenity or public access.

frame construction

Types of construction in which walls, partitions, floors, and roof are wholly or partly made of wood.


Stone, as sandstone, that may be cut freely in any direction without fracture or splitting.

French tile

Type of interlocking roof tile, heavily corrugated and formed with interlocking side joints and a rounded bull nose butt edge to engage the corrugations of the course immediately below.

frescoes (paintings)

Paintings made by the technique of fresco painting, which is a mural painting technique in which permanent pigments, dispersed in water, are painted on freshly laid lime plaster.

fresh water (water by property)

Water that does not contain a large amount of salt, as in ponds, lakes or streams.


Pulverized material made from flux, sand or other refractory that has been fused with heat but not fully vitrified; often used in making glazes and may contain a coloring ingredient which will give the glaze coloring throughout.


A principal ore of lead; lead sulfide (PbS). Often contains silver.

galvanized steel

Steel coated with a thin layer of zinc to prevent corrosion. The application may be effected by electroplating or spraying the steel with molten zinc, or by coating the heated steel with zinc powder.

gardens (open spaces)

Area of ground or open space where flowers, shrubs, trees, vegetables, or fruits are grown and cultivated.

garnet (mineral)

A general name for a type of mineral varying in color and hardness, including trisilicates of aluminum, magnesium, calcium, iron, manganese, vanadium, chromium, and sometimes sodium and titanium. Used for coating abrasive paper and cloth, for bearing pivots in watches, for electronics, and the finer specimens as gemstone.