As a rule their ingredients are not determinable by the unaided eye, but they are principally felspar and quartz as very minute particles.
The high translucency of "ivory porcelain" depends on the large proportion of felspar in the body.
Felspar is much used in the manufacture of porcelain by reason of its fusibility.
There are also placed in the anorthic class a potash-felspar called microcline, and a rare soda-potash-felspar known as anorthoclase.
Among the applications of felspar is that of pure orthoclase in the manufacture of artificial teeth.
Pure felsparis colourless, but the mineral is usually white, yellow, red or green.
Crystals of this kind are abundant at Le Bourg d'Oisans in Dauphine, where they are associated with rock-crystal, felspar and axinite in crevices in granite and mica-schist.
In many of their structural peculiarities they closely simulate the rhyolites, from which they differ in containing less potash and more soda, and in consequence less orthoclase felspar and more plagioclase.
The felspar breaks up into a mosaic in which albite, epidote or zoisite, quartz and garnet may often be identified.
They resemble the trachytes both in appearance and in structure, but their felspar is mostly plagioclase, not sanidine.
If felspar be present also, epidote may form, while part of the felspar recrystallizes as a species of the same mineral richer in alkalies or as mica.
The name is taken from that of the river Amazon, whence certain green stones were formedy obtained, but it is doubtful whether green felspar occurs in the Amazon district.
Their geological formation is metamorphic gneiss, veined withfelspar and quartz, and interspersed with reddish porphyrite.
The well known mineral felspar has a specific gravity intermediate between that of the coal and the shale, or stone, with which it is found intermixed.
The glaze of hard porcelain is a felspar rock: this being ground to a very fine powder, is worked into a paste with water mingled with a little vinegar.
The Kaolin occurs there in a bed, or perhaps a vein of beds of granite, or rather of that felspar rock called Pe-tun-tse, which exists here in every stage of decomposition.
The felspar gives strength to the biscuit, and renders it sonorous after being baked; while the china clay has the double advantage of imparting an agreeable whiteness and great closeness of grain.
The glaze consists of ground felspar or Cornish stone.
The biscuit of the hard porcelain made at the French national manufactory of Sevres is generally composed of a kaolin clay, and of a decomposed felspar rock; analogous to the china clay of Cornwall, and Cornish stone.
The following figures of a felspar and flint mill are taken from plans of apparatus lately constructed by Mr. Hall of Dartford, and erected by him in the royal manufactory of Sevres.
That most esteemed is the antient porphyry of Egypt, with a ground of a fine red colour passing into purple, having snow-white crystals of felspar imbedded in it.
On the other hand there are many granites, especially those in which felspar predominates, which crack and crumble down in the course of a few years.
The constituents of the stoneware are, that clay, the powder of calcined flints, and of the decomposed felspar called Cornish stone.
Sometimes the rock becomes of coarser texture and more crystalline, and the yellow color of the felspar gives place to a greenish tinge; and it sometimes also becomes a felspar of perfect cleavage, semitransparent, and white.
The granitoid rocks extend across Peel Sound into Prince of Wales' Island, in the form of a dark syenite composed of quartz, greenish white felspar passing into yellow, and hornblende.
It consists mainly of a grayish white granite, in which the felspar greatly predominates, but it is sometimes rendered dark by an excess of mica in minute black scales.
Most of them contained crystals of felspar and pyroxene.
A gutter leads from the mouth, showing signs of water-wear, and the blocks of trachyte are so loaded with glossy white felspar that I attempted to dust them before sitting down.
The pale tint of the green felsparwas also imitated in an opaque glass used for inlaying.
Notice that these substances do not occur in any definite order, but are scattered about through the stone irregularly, the felspar occurring in some specimens in larger crystals than in others.
The highly heated water decomposes the felspar and other volcanic rocks, and becoming slightly alkaline with the soda or potash these contain, it is enabled to form a silicious solution.
The ferromagnesian minerals crystallize comparatively early and have some idiomorphism; the felspar usually follows and only in part shows good crystalline outlines.
The felspar of the diorites ranges in composition from oligoclase to labradorite, and is often remarkably zonal, the external layers being more alkaline than the internal.
In many diorites the plagioclase felspar has crystallized before the hornblende, which consequently has less perfect outlines and forms irregular plates which enclose sharply formed individuals of felspar.
And in the dusty biscuit-making place of the potters, among the felspar mills in the furnace rooms of the metal workers, among the incandescent lakes of crude Eadhamite, the blue canvas clothing was on man, woman and child.
Three barges, smothered in floury dust, were being unloaded of their cargoes of powdered felspar by a multitude of coughing men, each guiding a little truck; the dust filled the place with a choking mist, and turned the electric glare yellow.
Why, for instance, when you change the composition of a felspar almost imperceptibly, do the angles change?
She would have it polished on one side only--the other should be rough to show the felspar in its natural state.
The reason of this is, that felspar is lighter than hornblende, and probably rises to the surface of the lava mass at the volcanic focus, and the basaltic lava is therefore reserved till the trachytic has been thrown off.
Potassium is an ingredient of felspar and mica, and hence is found in all the primary and in most of the volcanic rocks, as well as in the stratified rocks derived from them.
Sodium is a constituent of a variety of felspar which is somewhat abundant in volcanic rocks.
Granite is a rock of a light gray color, and is composed of quartz, felspar and mica, in variable proportions, confusedly crystallized together.
It is composed of Labrador felspar and hypersthene.
In some instances the felspar so predominates as almost to exclude the other minerals, when it is called felspathic granite.
When granite or limestone contains sulphuret of iron, the oxygen of the atmosphere, in connection with moisture, combines with the sulphur, forming sulphuric acid, by which limestone and the felspar of granite are rapidly decomposed.
We crossed one or two slight elevations wholly composed of compact felspar in blocks--forming ridges resembling an outcrop of strata, whereof the strike always pointed N.
At the Bloody Fall, the felspar rock is covered to the depth of six or seven hundred feet with a bed of greyish white, and rather tenacious clay, which being deeply intersected with ravines, forms steep hills.
When thefelspar assumed the appearance of a slaty claystone, which it did towards the base of the mountains on the banks of the river, we observed no copper in it.
The former are generally above the basalts; and the extraordinary development of felspar in that union, and the want of pyroxene, have always appeared to me very remarkable phenomena.
The presence of felspar seems to indicate that this small formation of sandstone (the sole secondary formation hitherto known in the Sierra Parime) belongs to red sandstone or coal.
Diorite forms the great mass of this stratum; it is of a dark green colour, granular, with small grains, and destitute of quartz; its mass is formed of small crystals of felspar intermixed with crystals of amphibole.
I observed in Mexico a very singular agglomerated felspar formation superposed upon (perhaps inclosed in) red sandstone, near Guanaxuato.
The May Dance’ is as sober as if it were designed for a panel in a public building; but in ‘The Dancing of the Felspar Fairies’ we have a vigorous abandon mingled with the conventionality of graceful poses.
The rock is an aggregate of felspar and hornblende, approaching in character some of the common varieties of sienite.
On the eastern side, where the felspar is in the greatest proportion, it is flesh-coloured, and its structure crystalline; the fractured surface of the mass being uneven like that of coarse granite.
A combination of fluorine and calcium, more fusible than felspar, and of a white colour, felspar being pink.
The felsparor China stone furnish the fluxing ingredients for fusing and binding.
Kaolin is used with China stone (a combination of felspar and quartz) to make porcelain, the finest and hardest paste known to potters.
The glaze requires stiffening, and the addition of ground flint or quartz, China stone or clay and felspar introduces alumina and silica and raises the fusing point.
Felspar laughs and tells them to take the papers then as the new law went into effect at four-thirty that afternoon.
Felspar introduces him as the Canadian representative of the firm whom he has never seen before.
Felspar is again furious and orders them out and the three go together leaving the company in an angry stupor.
John Felspar, junior partner of the firm of Felspar & Felspar, wine merchants.
Felspar congratulates him and the new waiter is called.
Felspar gives a few parting instructions to the new waiter and goes to bring the guests.
The four kinds of felspar which have been already named are compounds of silica with alumina, and another base which is either potash, soda, or lime.
Granite is a mixture of quartz, felspar, and mica in variable proportions, and the quality of the soil it yields depends on whether the variety of felsparpresent be orthoclase or albite.
The quality of the soil they yield is not however entirely dependent on the nature of the particular felspar which yields it, but is also intimately connected with the extent to which the decomposition has advanced.
This decomposition of felspar is the source of the great deposits of clay which are so abundantly distributed over the globe, and it takes place with nearly equal rapidity with potash and soda felspar.
Owing to the small quantity of felspar which it contains, and the abundance of the difficulty decomposable mica, the soils formed by its disintegration are generally inferior.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "felspar" in a variety of sentences. We hope that you will now be able to make sentences using this word.
