This contradicts the theory that the metallic iron of the dykes is the result of carbon acting upon the magnetite in them, and proves that the iron is the primary and the magnetite the secondary product.
The minerals at contact are quartz, biotite, magnetite and hornblende.
Magnetite and Kaolin are present in small quantities.
A coarse black rock carrying magnetite and pyrites in considerable quantities.
The magnetite is somewhat decomposed, the resulting hematite filling the spaces between the quartz grains.
The grains of the constituent minerals, quartz, feldspar and magnetite have an angular brecciated appearance; showing uneven extinction and strong crushing effects.
In Swedish Lapland, near the Arctic circle, are the great Gellivara, Kirunavara and Luossavara magnetite beds, among the largest in Europe.
The magnetite ore bodies which supply this industry lie in a band about 180 m.
The Archaean crystalline rocks abound in deposits ofmagnetite and red haematite, many of them very large and rich.
This property of volcanic rocks is well known, and is to be attributed to themagnetite in the groundmass.
In one or two of the Vanua Levu acid rocks showing polarity this can be also premised since magnetite is present in very slight degree.
On examining the character of the non-magnetic rocks it appears that almost all belong to two groups where magnetite might be expected to be scanty.
Magnetite is abundant, its grains corresponding in size to the augite granules.
The magnetite in the groundmass, although abundant, is not in greater quantity than is usually found in semi-vitreous basaltic rocks without polarity.
There is a good deal of magnetite and generally scanty residual glass.
The groundmass displays a plexus of felspars and augite-granules with much magnetite in grains and irregular patches.
Major Haig says that the compass becomes perfectly useless anywhere in the neighbourhood of one of the mountain-masses or extinct craters in Mauritius, and attributes this effect to the magnetite in the basalt.
But they are more often semi-vitreous, and display a considerable amount of dark smoky glass showing numerous magnetite rods and skeletal crystals with fibrous devitrification.
When the phenocrysts of olivine have blackish borders they are surrounded by a halo, as though the crystal had attracted the magnetite from the groundmass immediately around.
It is well known that the conversion of a hornblende crystal into an aggregate of pyroxene prisms and magnetite was long since experimentally effected by Doelter and Hussak by immersing the hornblende in molten basalt, andesite, &c.
The magnetite forms rather conspicuous masses between the veins of asbestos in Messrs.
In emery, magnetite in a granular form is largely associated with the corundum; and in certain kinds of mica magnetite occurs as thin dendritic enclosures.
Grains of magnetite occur in serpentine, as an alteration-product of the olivine.
By deoxidation, haematite may be converted into magnetite, as proved by certain pseudomorphs; but on the other hand magnetite is sometimes altered to haematite.
On weathering, magnetitecommonly passes into limonite, the ferrous oxide having probably been removed by carbonated waters.
Magnetite is a mineral of wide distribution, occurring as grains in many massive and volcanic rocks, like granite, diorite and dolerite.
The rotation for different coloured light from iron, nickel, cobalt and magnetite has been measured by Du Bois; in magnetite the direction of rotation is opposite to that of the other metals.
Liversidge has shown thatmagnetite is probably present.
In the red and brown iron ores and ochres ferric iron is present; in chalybite the iron is in the ferrous state; and in magnetite it is present in both forms.
Chalybite and the hydrated oxides dissolve very readily in hydrochloric acid; hæmatite and magnetite dissolve with rather more difficulty.
Magnetite is an abundant constituent, and a red garnet is apt to be present.
A greenish, fine-grained metamorphic rock in which chlorite is the principal mineral, but in which magnetite is a quite characteristic accessory constituent.
Some miles to the north of Providence in Rhode Island there is a hill known as Iron Hill composed in large part of black magnetite rock, the so-called Cumberlandite.
Magnetite is loadstone ore; the powder is reddish black, and the ore, dark brown to black.
An attraction which is confined to a very small spot and is lost in passing a few feet from it, is most likely to be caused by a boulder of ore or particles of magnetite with rock.
One of the common and important iron oxides with less iron than magnetite and no water as has limonite.
Magnetite is the ore, and it occurs in more or less irregular lenses and bands in granite and closely associated rocks of pre-Paleozoic Age.
Magnetite is the richest in iron, and limonite the poorest.
Thus limonite is never, hematite is usually, and magnetite is always, crystalline.
Iron is the only strongly magnetic element: magnetitecontains more iron than any other mineral, and it is the only strongly magnetic mineral.
Biotite is a common accessory in amphibolite, and garnet and magnetite frequently occur.
The most characteristic accessory constituents of norite, besides those already mentioned, are magnetite and chrysolite; though garnet, serpentine, and pyrite often occur.
Along with the magnetite is a band of iron pyrites, a few inches thick, with traces of copper.
Magnetite is not unknown in several of the remoter parts of Scotland, but the distance from fuel has hitherto prevented its application to economic purposes, at least in modern times.
The fine quality of the Magnetite ores is ascribed to their being mixed with calc-spar, thallite, hornblende, and other natural adjuncts advantageous for their reduction, so that the granular ores often require no other flux.
In magnetite the growths follow three axes at right angles to one another; in augite this is nearly, though not exactly, the case; in hornblende an angle of 57 deg.
The rock is a hornblendic granite, the constituents being quartz, felspar, biotite, hornblende and titanite, withmagnetite and a little apatite.
The original constituents are felspar, hornblende, quartz, apatite, ilmenite, magnetite and titanite.
About five per cent of the world's production of iron ore is from bodies of magnetite formed in association with igneous rocks.
Here themagnetite forms a great tabular vertical body lying between porphyry and syenite.
The magnetite crystals of these deposits interpenetrate with the other constituents of an igneous rock, commonly of a gabbro type, and the deposits themselves are essentially igneous rocks.
Crystalline magnetite and hematite are more resistant to erosion than almost any other type of rock, and stand out at the surface with proportional frequency.
In contact with steam at a red heat it forms magnetite and ammonia.
Magnetite is present in all of the lavas here described.
It consists of a light-greyish felsitic paste enclosing grains of smoke-quartz, crystals of sanidine, plagioclase and biotite, with a little magnetite and apatite.
Crystals of leucite with microliths and cavities darkened by magnetite dust; also, containing crystals of magnetite.
Melaphyre is a name given to the very dark varieties of altered augitic lavas, rich inmagnetite and chlorite.
Section of sodalite crystal from the lava of 1794, with belonites and crystals of magnetite enclosed.
Basalt is the most fusible of volcanic rocks, owing to the augite and magnetite it contains, so that it spreads out with a very slight slope when highly fused.
The prevailing varieties are magnetite and hematite.
Magnetite is found on the head of Ivy, in Madison county.
Since the power to attract other particles of iron is not apparent in all specimens of magnetite we must consider other more distinguishing characteristics.
The property possessed by magnetite of attracting other bits of iron appears to have been known to the ancients, and by them the name lodestone was applied to the mineral.
Apart from the evidence that is brought down by the magnetite and garnet, it would naturally be assumed that the gold had its primal source in the mountains back of the coast.
The magnetite is a conductor of electricity which is easily vaporized.
The lower (negative) electrode consists of an iron tube packed chiefly with magnetite (an iron oxide) and titanium oxide in the approximate proportions of three to one respectively.
The magnetite or luminous arc-lamp next appeared and met with considerable success.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "magnetite" in a variety of sentences. We hope that you will now be able to make sentences using this word. Other words: lodestar; lodestone; magnet; ore
