Magnetite occurs in great abundance in Western Australia, together with haematite, which would be of enormous value if cheap labour were available.
Goethite, limonite and haematite are found in New South Wales, at the junction of the Hawkesbury sandstone formation and the Wianamatta shale, near Nattai, and are enhanced in their value by their proximity to coal-beds.
Iron - haematite - is present almost everywhere.
Considerable quantities of the following minerals have been found: barytes (heavy spar), magnetite (magnetic iron ore), and pyrolusite (manganese dioxide) in Humboldt county; roofing slate in Esmeralda county; cinnabar (ore containing quicksilver) in Washoe county; haematite in Elko and Churchill counties; cerussite and galena (lead ores) in Eureka county; and wolframite (a source of tungsten) at Round Mountain, White Pine county.
Haematite is sometimes magnetic, and A.
By deoxidation, haematite may be converted into magnetite, as proved by certain pseudomorphs; but on the other hand magnetite is sometimes altered to haematite.
Mica, talc, chlorite, haematite), or in long blades or fibres (anthophyllite, tremolite, actinolite, tourmaline), and, when these have a well marked parallel arrangement in definite bands or folia, the rock will break far more easily along the bands than across them.
Garnet, tourmaline, staurolite, andalusite, actinolite, chloritoid or ottrelite, epidote, haematite, and if any of these is abundant its presence may be indicated by the name given the rock, e.g.
We may mention also graphiticschists containing dark scaly graphite (often altered forms of carbonaceous shales), and haematite-schists which may represent beds of ironstone.
It is found also in beds of iron ore, and the haematite mines of the Cleator Moor district in west Cumberland have yielded many extremely fine crystals, specimens of which may be seen in all mineral collections.
The quality of ore in the two ranges differs somewhat, that mined from the Vermilion Range being a hard specular or red haematite, while that taken from the Mesabi Range, largely red haematite, is much softer and in many localities quite finely comminuted.
To tin cast-iron articles they must be decarburetted superficially by ignition within a bath of ferric oxide (powdered haematite or similar material), then cleaned with acid, and tinned by immersion, as explained above.
In the neighbourhood of Millom there are blast furnaces and highly productive mines of red haematite ore.
Iron ore (haematite) is abundant.
The brownish colour of some slates is due to limonite and haematite, but magnetite occurs in the darker coloured varieties.
The kat is not unusual in Syria (44), and among the haematite weights of Troy (44) are nine examples, average 144, but not of extreme varieties.
(It is better to avoid the name Babylonian, as it has other meanings also.) There are no weights dated before the Assyrian bronze lion weights (9, 17, 19, 38) of the 11th to 8th centuries B.C. Thirteen of this class average 127.2 for the shekel; 9 haematite barrel-shaped weights (38) give 128.2; 16 stone duck-weights (38), 126.5.
127) are found among the haematite weights of Troy (44), including the oldest of them.
Two haematite weights from Troy (44) show 86 and 87.2.
In Syria haematite weights are found (30) averaging 198.5, divided into 99.2, 49.6 and 24.8; and the same division is shown by gold rings from Egypt (38) of 24.9.
Probably before any Greek coinage we find this among the haematite weights of Troy (44), ranging from 208 to 193.2 (or 104-96.6), i.e.
The ore is chiefly haematite, and has been developeci from antecedent ferruginous sedimentary deposits, through concentration and purification by ground water.
But in the recent and great development of the iron industry the red haematite ores have been overwhelmingly predominant.
From 1889 to 1907 the average yearly percentages of the red haematite, brown ores, rnagnetite and carbonate in the total ore production were respectively 824, I0I, 7.1 and 0.4.
With the reservations that only in the case of certain red haematite bedded deposits can any estimate be made of relative accuracy, say within 10%; that the concentration deposits of brown ore can be estimated only with an accuracy represented by a factor varying between 0.7 and 3; and that the great Lake Superior and the less known Adirondack deposits can be estimated within 15 to 20%, the total supply of the country was estimated at 79,594,220,000 long tons73,21o,415,000 of which were credited to haematite ores and 5,054,675,000 to magnetite.
The iron ore (found chiefly in the region of which Birmingham is the centre) is primarily red haematite and (much less important) brown haematite; though as regards the latter Alabama ranked first among the states of the Union in 1905 (with 781,561 tons).
It is never crystallized, but may have a fibrous or microcrystalline structure, and commonly occurs in concretionary forms or in compact and earthy masses; sometimes mammillated, botryoidal, reniform or stalactitic. The colour presents various shades of brown and yellow, and the streak is always brownish, a character which distinguishes it from haematite with a red, or from magnetite with a black streak.
In many cases it has been formed from other iron oxides, like haematite and magnetite, or by the alteration of pyrites or chalybite.
On the other hand there are certain forms of ferric hydrate containing less water than limonite and approaching to haematite in their red colour and streak: such is the mineral which was called hydrohaematite by A.
It probably represents the partial dehydration of limonite, and by further loss of water may pass into haematite or red iron ore.
Within the Carboniferous rocks, but due to the action of various agencies long after their deposition, are important ore formations; such are the Rio Tinto ores of Spain, the lead and zinc ores and some haematite of the Pennine and Mendip hills and other British localities, and many ore regions in the United States.
They are four important iron ores, magnetite, haematite, limonite and siderite, and one of less but still considerable importance, pyrite or pyrites.
Haematite, or red haematite, Fe 2 0 3, contains 70% of iron.
In some cases the iron-bearing mineral, such as magnetite or haematite, can be separated from the gangue after crushing, either mechanically or magnetically, so that the part thus enriched or " concentrated " alone need be smelted.
- The Archaean crystalline rocks abound in deposits of magnetite and red haematite, many of them very large and rich.
The rich beds near Lake Superior, chiefly red haematite, yielding at present about 55% of iron, are thought to contain between II and 2 billion tons, and the red and brown haematites of the southern states about to billion tons.
The mountains consist here of an ancient laminated micaceous quartzite, which is in parts a flexible sandstone known as itacolumite, and in parts a conglomerate; it is interbedded with clay-slate, mica-schist, hornblende-schist and haematite-schist, and intersected by veins of quartz.
Under all these three conditions the diamond is associated with fragments of the rocks of the country and the minerals derived from them, 'especially quartz, hornstone, jasper, the polymorphous oxide of titanium (rutile, anatase and brookite), oxides and hydrates of iron (magnetite, ilmenite, haematite, limonite), oxide of tin, iron pyrites, tourmaline, garnet, xenotime, monazite, kyanite, diaspore, sphene, topaz, and several phosphates, and also gold.
At Sao Joao da Chapada, in Minas Geraes, diamonds occur in a clay interstratified with the itacolumite, and are accompanied by sharp crystals of rutile and haematite in the neighbourhood of decomposed quartz veins which intersect the itacolumite.
Considerable veins of haematite of good quality occur both in the Red Sea hills and in Sinai.
The essential coloring materials are, for blue, copper; green, copper and iron; purple, cobalt; red, haematite; white, tin.
In the earlier part of the prehistoric age there was a soft brown ware with haematite facing, highly burnished.
This was burnt mouth-down in the oven., and the ashes on the ground reduced the red haematite to black magnetic oxide of iron; some traces of carbonyl in the ash helped to rearrange the magnetite as a brilliant mirror-like surface of intense black.
Red ochre, for which there is only a limited market, is mined on Ormuz, Abu Musa and other islands in the Gulf; salt, as deposits, on Ormuz and Qishm I., and by evaporation, near Mohammerah, Fao and elsewhere on both sides of the Gulf; gypsum is widely distributed throughout the Gulf; iron, as haematite and pyrites, widely found through the Ormuz series.
The ore is partly a clay ironstone, like that occurring in the Coalmeasures of England, partly an oxide of iron or haematite, and it generally contains phosphorus.
The ore is a red haematite occurring in slate.
HAEMATITE, or Hematite, a mineral consisting of ferric oxide (Fe203), named from the Greek word -aiµa, "blood," in allusion to its typical colour, whence it is called also red iron ore.
When crystallized, however, haematite often presents a dark colour, even iron-black; but on scratching the surface, the powder of the streak shows the colour of dried blood.
Haematite crystallizes in the rhombohedral system, and is isomorphous with corundum (Al203).