(Creta) is a white earth found plentifully in Britain, France, Norway, and other parts of Europe, said to have been anciently dug chiefly in the island of Crete, which thence received its name of Creta. Chalk readily imbibes water; and hence masses of it are employed for drying precipitates, lakes, earthy powders that have been levigated with water, and other moist preparations. Its economical uses in cleaning and polishing metallic or glass utensils are well known. In this case it is powdered and washed from any gritty matter it may contain, and is then called whiting.

Black Chalk, a name given by painters to a species of earth with which they draw on blue paper. It is found in pieces of from two to ten feet in length, and from four to twenty inches in breadth, generally flat, but somewhat rising in the middle, and thinner towards the edges, commonly found in large quantities together. While in the earth it is moist and flaky; but being dried, it becomes considerably hard and very light, but always breaks in some particular direction; and, if attentively examined when first broken, it appears of a striated texture. To the touch it is soft and smooth, stains very freely, and by virtue of its smoothness makes very neat marks. It is easily reduced into an impalpable powder, without any diminution of its blackness. In this state it mixes easily with oil into a smooth paste; and being diffused through water, it slowly settles in a black slimy or muddy form; properties which make its use very convenient to painters, both in oil and water-colours.

Red Chalk, an earth much used by painters and artificers, and common in the colour shops. It is of a fine, even, and firm texture; very heavy and very hard; of a pale red on the outside, but of a deep dusky chocolate colour within. It adheres firmly to the tongue, is perfectly insipid to the taste, and makes no effervescence with acids. Chalk-Stones, in Medicine, signify the concretions of calcareous matter in the hands and feet of people violently afflicted with the gout.