Chalk vs. Sandstone — What's the Difference?

Chalk is a soft, white, porous, sedimentary carbonate rock, a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton which had fallen 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.

Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks.Most sandstone is composed of quartz or feldspar (both silicates) because they are the most resistant minerals to weathering processes at the Earth's surface, as seen in the Goldich dissolution series.

A white soft earthy limestone (calcium carbonate) formed from the skeletal remains of sea creatures.

A sedimentary rock formed by the consolidation and compaction of sand and held together by a natural cement, such as silica.

Short for French chalk

A sedimentary rock produced by the consolidation and compaction of sand, cemented with clay etc.

Write or draw with chalk

A rock made of sand more or less firmly united. Common or siliceous sandstone consists mainly of quartz sand.

Charge (drinks bought in a pub or bar) to a person's account

A sedimentary rock consisting of sand consolidated with some cement (clay or quartz etc.)

A soft compact calcite, CaCO3, with varying amounts of silica, quartz, feldspar, or other mineral impurities, generally gray-white or yellow-white and derived chiefly from fossil seashells.

A piece of chalk or chalklike substance in crayon form, used for marking on a blackboard or other surface.

(Games) A small cube of chalk used in rubbing the tip of a billiard or pool cue to increase its friction with the cue ball.

A mark made with chalk.

Chiefly British A score or tally.

To mark, draw, or write with chalk

To rub or cover with chalk, as the tip of a billiard cue.

To make pale; whiten.

To treat (soil, for example) with chalk.

(uncountable) A soft, white, powdery limestone (calcium carbonate, CaCO3).

(countable) A piece of chalk, or nowadays processed compressed gypsum (calcium sulfate, CaSO4), that is used for drawing and for writing on a blackboard (chalkboard).

Tailor's chalk.

A white powdery substance used to prevent hands slipping from holds when climbing, or losing grip in weight-lifting or gymnastics, sometimes but not always limestone-chalk, often magnesium carbonate (MgCO3).

A platoon-sized group of airborne soldiers.

The favorite in a sporting event.

The prediction that there will be no upsets, and the favored competitor will win.

To apply chalk to anything, such as the tip of a billiard cue.

To record something, as on a blackboard, using chalk.

To use powdered chalk to mark the lines on a playing field.

(figuratively) To record a score or event, as if on a chalkboard.

To manure (land) with chalk.

To make white, as if with chalk; to make pale; to bleach.

A soft, earthy substance, of a white, grayish, or yellowish white color, consisting of calcium carbonate, and having the same composition as common limestone.

Finely prepared chalk, used as a drawing implement; also, by extension, a compound, as of clay and black lead, or the like, used in the same manner. See Crayon.

To rub or mark with chalk.

To manure with chalk, as land.

To make white, as with chalk; to make pale; to bleach.

A soft whitish calcite

A pure flat white with little reflectance

Amphetamine used in the form of a crystalline hydrochloride; used as a stimulant to the nervous system and as an appetite suppressant

A piece of chalk (or similar substance) used for writing on blackboards or other surfaces

Write, draw, or trace with chalk