Sidewalk Chalk Blue

Sidewalk chalk

Sidewalk chalk is typically large and thick sticks of chalk made of calcium sulfate (gypsum), instead of calcium carbonate. It comes in multiple colors and is mostly used for drawing on pavement or concrete sidewalks, frequently four square courts or hopscotch boards. Blackboard chalk, typically used in educational settings, is shorter and thinner than sidewalk chalk.

Sidewalk

A sidewalk, pavement or footpath is a footpath along the side of a road or street, designed primarily for pedestrians and low-speed personal transporters such as mobility scooters and postal NEVs. Sidewalks are usually paved by concrete, pavers, bricks, tiles, stones or asphalt, and are normally slightly elevated from the roadway and separated from motor vehicle lanes by a curb or gutter. There may also be a planted strip between the sidewalk and the roadway and between the roadway and the adjacent buildings, land lots and private properties.

Chalk

Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed under the sea by the accumulation and lithification of hard parts of organisms, mostly microscopic plankton, which had settled to the sea floor. Chalk is common throughout Western Europe, where deposits underlie parts of France, and steep cliffs are often seen where they meet the sea in places such as the Dover cliffs on the Kent coast of the English Channel.

Blue

Blue is one of the three primary colours in the RGB (additive) colour model, as well as in the RYB colour model. It lies between violet and cyan on the spectrum of visible light. The term blue generally describes colours perceived by humans observing light with a dominant wavelength between approximately 450 and 495 nanometres. The clear daytime sky and the deep sea appear blue because of an optical effect known as Rayleigh scattering. An optical effect called the Tyndall effect explains blue eyes. Distant objects appear more blue because of another optical effect called aerial perspective.

sidewalk

Noun

1. A paved footpath located at the side of a road, for the use of pedestrians.
2. Any paved footpath, even if not located at the side of a road.

chalk

Noun

1. A soft, white, powdery limestone (calcium carbonate, CaCO3).
2. A piece of chalk, or nowadays processed compressed gypsum (calcium sulfate, CaSO4), that is used for drawing and for writing on a blackboard (chalkboard).

Verb

1. To apply chalk to anything, such as the tip of a billiard cue.
2. To record something, as on a blackboard, using chalk.

blue

Adjective

1. Of a blue hue.
2. Depressed, melancholic, sad.

Noun

1. The colour of the clear sky or the deep sea; the colour midway between green and violet in the visible spectrum and one of the primary additive colours.
2. Anything coloured blue, especially to distinguish it from similar objects differing only in colour.