Chalk vs. Talc — 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.

Talc, or talcum, is a clay mineral, composed of hydrated magnesium silicate with the chemical formula Mg3Si4O10(OH)2. Talc in powdered form, often combined with corn starch, is used as baby powder.

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

A fine-grained white, greenish, or gray mineral, Mg3Si4O10(OH)2, having a soft soapy feel and used in talcum and face powder, as a paper coating, and as a filler for paint and plastics.

Short for French chalk

To apply this substance to (a photographic plate, for example).

Write or draw with chalk

(obsolete) Originally a large range of transparent or glistening foliated minerals. Examples include mica, selenite and the hydrated magnesium silicate that the term talc generally has referred to in modern times (see below). Also an item made of such a mineral and depending for its function on the special nature of the mineral (see next). Mediaeval writers adopted the term from the Arabic.

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

(obsolete) A microscope slide made of a plate of mica, generally in use from the start of modern microscopy until the early nineteenth century, after which glass slides became the standard medium.

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 soft mineral, composed of hydrated magnesium silicate, that has a soapy feel and a greenish, whitish, or grayish color, and usually occurs in foliated masses.

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

Talcum powder.

(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.

(transitive) To apply talc to.

A mark made with chalk.

A soft mineral of a soapy feel and a greenish, whitish, or grayish color, usually occurring in foliated masses. It is hydrous silicate of magnesia. Steatite, or soapstone, is a compact granular variety.

Chiefly British A score or tally.

A fine grained mineral having a soft soapy feel and consisting of hydrated magnesium silicate; used in a variety of products including talcum powder

To mark, draw, or write with chalk

Apply talcum powder to (one's body)

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