Perhaps the best, or at least the most convenient, test for kaolin is the argillaceous odor, the odor of moistened clay.
By exposure to the weather, feldspars gradually lose their alkalies and lime, become hydrated, and are changed to kaolin or common clay.
That kaolin is the basis of common clay is proved by the argillaceous odor, which is so characteristic of moist clay.
Kaolin is the most abundant of all the hydrous silicates, and it is the basis and often the sole constituent of common clay,—a very common mineral, but rarely pure.
Mica schist usually consists, as in this instance, of mica and quartz; but it may be composed of mica alone; and sometimes kaolin or clay takes the place of the quartz, forming argillaceous mica schist.
Pure kaolin clay is white and impalpable, like China clay; but pure clays are the exception.
Kaolin is the finest porcelain clay, and the best comes from China, Japan or France.
Deposits of Kaolin or China clay are usually so found.
This was the more remarkable because kaolin had not then been discovered in this country.
He journeyed to Cornwall, and was successful in getting kaolin for chinaware.
This change may be illustrated by quoting the analysis of a kaolin clay formed by the disintegration of orthoclase felspar.
The attendant on the east side of the rug having completed his twelve sticks, painted them white with kaolin finely ground and mixed with water.
As a rule the crystals are roughly developed and rude columnar masses are common, these being frequently altered partially to kaolin or mica.
Considerable quantities of aluminium are obtained from the kaolin deposits in the vicinity.
A very shallow porous tray (made ofkaolin and silica) is filled with red lead paste, an electrode of rolled sheet lead is placed on its surface, and over this again is placed a second porous tray filled with paste.
Kaolin thus seems to be the best ore, and it would undoubtedly be used were it not for the fatal objection that no satisfactory process has yet been discovered for preparing pure alumina from any mineral silicate.
The current was passed through this "match" until the kaolin strip became heated sufficiently to become a conductor itself.
About this time kaolin was discovered in Cataluna, and the Count was particularly anxious that this native product should be utilised at Alcora.
Impurities of the bauxite ores are the small quantities of iron and titanium present in the original rocks, together with the kaolin which has not been broken up.
The breaking up of kaolin accompanied by the removal of silica is not characteristic of temperate climates, though many clays in these climates show some bauxite.
Near the surface there may be an increase in silica,--probably due to a reversal of the usual conditions by a slight leaching of alumina, thus concentrating the denser masses of kaolin which have not been decomposed.
It is usually associated withkaolin and frequently with quartz, and is believed to have been formed by surface alterations.
Deposits of bauxite usually contain as impurities silica (in the form of kaolin or hydrous aluminum silicate), iron oxide, and titanium minerals, in varying proportions.
In the weathering of rocks high in alumina, and low in iron minerals and quartz, deposits of residual clay or kaolinnearly free from iron oxide and quartz are formed.
It is the overflow from the kaolinworks at Lee Moor.
China-clay or kaolinis obtained from highly decomposed granite, and consists of the disintegrated and metamorphosed felspar of that rock.
Kaolin is found elsewhere, in Devon, on the fringe of Dartmoor.
In precisely the same year kaolinwas discovered at St. Yrīeix, near Limoges.
The kaolin may be washed away from its original site, and deposited in hollows or lakes to form beds of white clay, such as pipe-clay; in this case it is always more or less impure.
It is almost always more than would be the case if the rock consisted of kaolin mixed with muscovite.
The felspar decomposes into kaolin and quartz; its alkalis are for the most part set free and removed in solution, but are partly retained in the white mica which is constantly found in crude china-clays.
It is certain, however, that the finer-grained rocks are richest in alumina, and in combined water; hence the inference is clear that kaolin or some other hydrous aluminium silicate is the dominating constituent.
Some of the earliest discoveries of kaolin in Europe were at Aue, near Schneeberg in Saxony, and at St Yrieix, near Limoges in France.
In order to prepare kaolin for the market, the china-clay rock is broken up, and the clay washed out by means of water.
The kaolin confers plasticity on the paste and secures retention of form for the ware when exposed to the heat of the kiln, whilst the petuntse gives the translucency so characteristic of porcelain.
Only a hard paste, or kaolin ware, is acknowledged by experts to be genuine porcelain.
Different combinations of kaolin clays and phosphates; a ware which in the porcelain trade is known as bone china," replied Mr. Croyden.
Well, as you can imagine, after kaolin was discovered the secret gradually leaked out, and everybody went to work at making china.
Already I have told you that the Chinese made beautiful porcelains from kaolin and petuntse, two clays which produced a hard, semi-transparent china," he began.
Kaolin being simply decomposed feldspar, and the glaze applied to it being practically pure feldspar, the product is merely a mass of feldspar melted in the fire until all the metals it contains except platinum are eliminated.
The phosphate of lime that is mixed with the kaolin renders the body of the ware more porous and elastic.
By putting the kaolin and the petuntse together in the right proportions, moulding the clay, and afterward applying to it a glaze of some sort the Chinese made their porcelain, and very beautiful porcelain it was.
Now you can imagine with a background of such progress at china-making, what a furore and transformation followed when kaolin was discovered.
Yes, as far back as 1515 pottery, as I told you, was made in Venice; and with the discovery of kaolin Venetian merchants imported the true clay which did not exist in Italy, and manufactured both hard and soft paste.
It was not until kaolin was discovered in 1765 and taken from the section about St. Yrieix that hard paste, or pâte dure, was made in France.
Kaolin is dissolved feldspar, deposited from the granite which has yielded to atmospheric and aqueous influences.
If the bottom be sufficiently denuded it is seen to be white and smooth as a girl's shoulder--the kaolinthat underlies all.
At the bottom of the pits are plugs, and so soon as the settled kaolin is sufficiently thick, these plugs are withdrawn, and the clay, now of the consistency of treacle, is allowed to flow into tanks at a lower level.
Kaolin is the Chinese word given to the clay from which hard porcelain is made, though here it is generally called China or Cornish clay.
The Chinese and Japanese, with which may be assimilated the German and French, all of them made of kaolin and felspar, sometimes with an addition of quartz.
This is a kind of hard porcelain made from a mixture of kaolin and felspar, in which the degree of hardness or fusibility is regulated by the proportion of one material towards the other.
The English porcelain, the body of which is made, like the hard, from kaolin and Cornish stone, but differing from it by the addition of a large proportion of calcined bones.
Thirdly, Cornwall, a county in which I have not been, but which is sufficiently known as possessing kaolinand granite.
The snows and rain detaches from this surface of the rock the white earth, which being deposited in the plain below, forms a stratum of kaolin more or less pure, according to the circumstance of the place.
Magnetite and Kaolin are present in small quantities.
In the hand specimen it is an apparently pure orthoclase but in the thin section small scattered quartz grains are observed; as well as the alteration products, Kaolin and sericite.
However, it is known that before the discovery of kaolin in Europe the English and Dutch used to send over to China designs to be put on wares that were ordered.
The discovery during this period of the properties of kaolin and the effort to imitate by artificial means the luminous beauties of jade, pointed the way to the evolution of a white translucent porcelain body.
Four pounds of the standard mixture of equal parts of DDT and kaolin were used to 100 gallons of water in all applications.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "kaolin" in a variety of sentences. We hope that you will now be able to make sentences using this word.
