GLOSSARY

Terms used in the California Bricks web site are defined here.

Angled. This is a directional term for the orientation of marks on the surface of the brick, upon which the mark, such as a groove, is at some angle relative to the long edge of the brick.

Bark. A type of rough texture made on the sides and/or ends of a brick to simulate the rough bark of a tree. Bark texture is made by passing a ribbon of wet clay by a twisted wire or saw blade.

Bat. A part of a brick. Half a brick is known as 4 1/2-inch bat. If longer than 4 1/2 inches but less than 9 inches, it is called a 3/4 bat.

Branded Name. The name, logo, or symbol imprinted on the surface of the brick. The name may be the maker's name, company name, brand name, type of brick, logo, symbol, destination, date, phrase, or any design pattern. The brand may be recessed in the face or raised on the face of the brick. Branded names may be placed on any side or face of the brick.

Brick. A solid unit of clay, either burned or sun-dried, and about 8 x 3 3/4 x 2 1/4 inches in size.

Brush. A type of rough texture made on the sides and/or ends of a brick using a fine wire brush. In a hand-mold brick, the sides and ends of a brick were brushed with a wire brush by hand. This made fine striations on the surface of the brick that were not usually straight but angled or undulatory. Some striations may have been truncated by repeated brushing. In the stiff-mud process, a ribbon of wet clay passed by a wire brush, leaving straight fine striations on the surface of the brick.

Clasts. Larger visible minerals, rocks, or brick fragments floating in the finer clay body. Some of these clasts are natural components of the clay, some may have been purposely added to the mix, which is referred to as grog. Some clasts are desirable to aid in the binding of the clay material. The diagnostic clasts are the natural ones that help to determine the source of the clay material.

Clinker. Black or brown, blistered, and often warped and twisted brick, usually tossed on the reject pile at the plant. These bricks were prematurely fired or overfired in the kiln. Their unique color, texture, and shape made them popular for use as decorative bricks in the early part of the 20th century.

Common Brick. A type of brick usually made of clay or shale and fired in the kiln. The surface of the brick is natural, not finished for appearance as a face brick.

Conveyor-Belt Impressions. If the wet clay brick is placed on a conveyor belt, the surface of the brick will be imprinted with a pattern transferred from the belt. This may appear as a fine screen pattern on one side of the brick. Typical patterns are tiny squares, diamonds, rectangles, or circles.

Corner. The point formed by the intersection of three edges of a brick.

Curved. This is a directional term for the orientation of marks on the surface of the brick, upon which the mark, such as a groove, has a curved path. An example would be the curved wire-cut grooves on the ends of the brick.

Dry Press Method. Clay is ground in a dry pan, then taken directly to the dry press machine to be pressed into bricks under enormous pressure. The bricks are very dense and have smooth surfaces and sharp corners. No dryer is needed. Bricks go directly to the kiln to be fired.

Edge. The line formed by the intersection of two sides or a face and a side of a brick.

Enameled Brick. A type of brick used for the exterior of buildings and for other decorative purposes. The brick is made in a mold and a glaze is applied directly to the surface of the brick. The brick is fired in a kiln.

Efflorescence. Also known as scum, a white deposit that forms on the surface of the brick made from clays high in sulfates of lime (calcium sulfate) or other soluble salts. They appear when drying and can be permanently fixed by firing in the kiln. Bricks with efflorescence are considered inferior in quality.

End. The short narrow sides of a brick.

End Cut. A type of cutting process in which the continous bar of clay is cut along the short side of the brick. Such bricks are called end-cut bricks.

Face. The long and widest sides of a brick. In a hand-molded brick, there is a top face, which is the face at the top of the mold, and a bottom face, which is the face at the bottom of the mold.

Face Brick. A type of brick made accurately to size and finished for appearance because it is used on the outside walls or on the front face of buildings. The surface is made to appear smooth or textured by artificial processes. The brick is fired in a kiln.

Face Cut. A type of cutting process in which the continuous bar of clay is cut along the face of the brick. Such bricks are called face-cut bricks.

Fire Brick. A type of brick made of plastic clay and flint clay. These are refractory clays that can withstand very high temperatures. The brick is usually white or in shades of brown. Fire brick is used for lining furnaces, fire places, and chimneys. The dimensions of a fire brick is about 9 x 4 1/2 x 2 1/2 inches.

Flashed or Flashing. The multiple colors produced on the sides and ends of a brick by controlling the reducing conditions, or closed fires, in the kiln and rapidly increasing the temperature near the end of the firing. Flashed colors may penetrate into the interior of the brick as much as 1/2 inch or more depending on the length of firing at high temperatures under reduced conditions. A broken cross-section of the brick will display a red core with surrounding rings of yellow, brown, blue, and black. On the surface, flashing may display colorful patterns of yellow bands on red or red centers with borders of yellow, brown, and black.

Frog. The indentation or depression in the face of a brick made for the purpose of holding mortar. There may be a single frog or multiple numbers of frogs on a face. Frogs may be shallow or deep with flat bottoms or with V- or U-shaped cross-sections. Some frogs have beveled edges. Frogs may be rectangular, square, oval, round, or triangular in shape.

Glazed Brick. A type of brick, uniform in size, and made in a mold. The surface is applied first with a slip and then glazed. It is fired in a kiln. Glazed brick is used where sanitary conditions are required such as kitchens and restrooms.

Grog. Coarse-grained material, such as ground quartz, feldspar, other minerals, rocks, or crushed brick, which are mixed with fire clay to increase binding strength and reduces shrinkage in the manufacture of fire brick. Grog appears as angular to subangular clasts, 1/8 to 1/2 inch across.

Hand-Molded Process. Clay and water mixture is placed into a mold and pressed by hand. The bricks are dried and fired in a kiln.

Lamination Cracks. Cracks in the brick caused by the auger machine, which cuts and mixes the clay material in the pug mill. The clay body will display laminations or distinct layers with lamination or curved cracks. There are two types of lamination cracks: round and S-shaped cracks. Round cracks are formed when the blades or knives of the auger cut the clay into a long ribbon, or band of clay, and turn or twist it like a corkscrew. The cracks appear as curved cracks on the surface of the brick as well as in the interior. S-shaped cracks are caused by the pugging shaft of the auger where a conical hole is formed at the end of the shaft. This hole is flattened into a horizontal slit when the clay ribbon is forced through the auger die, and the twisting of the clay by the auger shaft deforms the slit into an S-shaped crack. Both round and S-Shaped cracks can appear together in the same brick. A cross-section of the interior of the brick will show folded laminations in the clay body.

Lip. In a hand-molded brick, where excess clay is scraped off of the top of the mold, some of the excess clay is pushed down around the top edges of the brick, leaving a thickened edge that protrudes slightly from the sides and ends of the brick. This is called the lip, which is an indication that the brick was hand-molded.

Longitudinal. This is a directional term for the orientation of marks on the surface of brick, upon which the mark, such as a groove, is parallel to the long side of the brick.

Matt. A type of rough texture made on the sides and/or ends of a brick by sharp points. The surface of the brick is lightly and randomly scratched, giving the brick surface a matt-like finish.

Mold-Marks. In a hand-molded brick, accidental marks on the surface of the brick caused by the brick mold are indications of the hand-molded process. The sides of the mold may have imperfections that are imprinted on the bottom, sides, or ends of the brick. These imperfections may put transverse scratch marks or grooves on the sides and ends of the brick when the wet brick is dumped out of the mold.

Norman Brick. Longer than standard sized brick, usually about 12 x 4 x 2 3/8 inches.

Paving Brick. A type of brick made for high crushing strength. It is made from crushed shale, molded, and fired in a kiln until annealed or vitrified into an extremely hard brick. Because this brick is more expensive than common brick, it is not generally used in buildings, but for paving streets, sidewalks, and gutters.
Pressed. A type of process and texture that produces a smooth, slick surface on all sides of a brick. The already cut or hand-molded brick is placed into a pressing machine that presses all sides of the brick with great force. This often destroys any marks previously made by the cutting machines or molds. The grains on the surface of pressed brick will appear flattened. Lines or patterns from the brick press will usually appear as a distinguishing feature for pressed brick.

Pressed Brick. A type of brick that is dry pressed and fired in a kiln. Pressed brick is usually very compact and dense. The surface is smooth and artifically colored. The edges may be rounded. They are used for facing the fronts of buildings.

Repressed Lines. On a pressed brick along the edges are secondary straight lines parallel to the edges of the brick, forming what appears to be a marginal border around the side of the brick. This line is an artifact of the brick press.

Roman Brick. Longer and thinner than standard sized brick, usually about 12 x 4 x 1 1/2 inches.

Round Edge. On a round edge pressed brick, the edges will be rounded, which was formed by the mold of the brick press. The round edges are usually bordered with repress lines that appear on the sides or faces of the brick.

Rough Texture. A type of texture found on face bricks and purposely made by the use of sharp points gouging the surface of the wet clay ribbon as it passes through the die of the extruding machine. Rough textures may be evenly or irregularly spaced grooves, that may or may not be continuous across the side of the brick. Different types of points were used, such as saw blades, nails, or wire, to make different types of rough textures. Names were given to different types of rough textures such as Rug, Ruffled, Bark, and Brush.

Rug. A type of rough surface texture purposely made on the sides and/or ends of a brick to simulate a rug pattern. The surface of the brick is gouged by sharp points as the ribbon of clay passes through the die of an extruding machine. The points may be nails, saw blades, or twisted wire. The grooves are cut straight and deep perpendicular to the long side of the brick. Variations in the number of grooves, groove spacings, and depth are made by adjusting the points.

Ruffled. A type of rough surface texture purposely made on the sides and/or ends of a brick to simulate a ruffled pattern. The surface The surface of the brick is gouged by sharp points as the ribbon of clay passes through the die of an extruding machine. The points may be nails, a saw blade, or twisted wires. The grooves are cut straight and deep perpendicular to the long side of the brick. Variations in the number of grooves, groove spacings, and depth are made by adjusting the points. Unlike the rug texture, ruffled texture tends to hide or cover the grooves with the strips of loose clay gouged out of the groove.

Sand-Lime Brick. A type of brick made of a mixture of sand and lime, molded, and fired in a kiln. Because this brick has a low crushing strength, it is not used where strength is important. It is used to face the fronts and sides of buildings.

Sand-Struck or Sand-Molded. Sand is used to coat the brick or mold for lubrication to prevent the wet brick from sticking to the mold. The brick will usually have a fine coating of sand on the bottom face, sides, and ends of the brick.

Side. The long narrow sides of a brick.

Side Cut. A type of cutting process in which the continous bar of clay is cut along the long side of the brick. Such bricks are called side-cut bricks.

Stack Indentations. Slight depressions and elevations on the sides of a brick caused by the weight of stacking bricks inside the kiln. Sides of brick can have one or two stack indentions per side of brick. Softer brick can be warped by deep stack indentions. The width of stack indentions depends on how the bricks were stacked. Bricks stacked with sides normal to each other will make stack indentions the same width as the shortest side of the brick. Bricks stacked with faces normal to each other will make stack indentions the same width as the short side of the face. Bricks stacked all in the same plane can have stack indentions of varying widths. Bricks stacked at angles to each other will make stack indentations that are angled.

Soft-Mud Process. Clay and water is mixed in a pug mill and placed in a mold and pressed by machine, making four to six bricks at a time. The bricks are dried and fired in a kiln.

Stiff-Mud Process. Clay and water is mixed in a pug mill or wet pan and put into an auger machine, which forces the clay through a die of the extruding machine and comes out as a continuous bar of clay, which is cut by wire into bricks. The bricks are dried and fired in a kiln.

Strike. A process used in hand-molded brick to remove excess clay from the top of the mold by scraping off the clay with a piece of wood, blade, or wire. The scraping makes grooves in the direction of the strike, which may be longitudinal, transverse, or angles relative to the long edge of the brick. This is one of the features that indicates a hand-molded brick.

Transverse. This is a directional term for the orientation of marks on the surface of the brick, upon which the mark, such as a groove, is perpedicular to the long side of the brick, or parallel to the short side of the brick.

Velour Texture. A type of rough surface texture produced in wire-cut bricks, which gives the surface of the brick a fine wrinkled or torn apart texture. The grain of velour texture can be in any direction on the surface of the brick.

Water-Struck. Water is used to lubricate brick or mold to prevent the wet brick from sticking to the mold. The brick will usually have a smooth surface on the bottom face, sides, and ends of the brick.

Wire-Cut. This is a process of using a wire to cut the brick from the continuous clay ribbon extruded from an extruding machine. The wire cuts may be straight or they may be curved depending on the type of equipment used. Wire-cut surfaces display wire-cut grooves in the direction of the cut and leaves a slightly rough texture on the surface of the brick often referred to as velour texture.

GLOSSARY

Comments or questions are welcomed. Please send email to Dan Mosier at danmosier@earthlink.net.

Comments or questions are welcomed.
Please send email to Dan Mosier at danmosier@earthlink.net.