Definition and origin
Limonite is a common rock that is widely used as a raw material. In a chemical sense, it is a hydrated mixture of iron oxides. It is used for further smelting of iron and steel. That is why this mineral is one of the most important. Naturally, its extraction reaches enormous proportions. It is mined by all countries in whose territory limonite deposits were found.
Briefly, the composition of limonite is as follows:
lepidocrocite;
goethite;
hematite;
adsorbed water.
The name limonite comes from the Greek “lemon” – meadow. Of course, this name was initially applied not to mountain ores, but to meadow and swamp ores. In fact, this mineral has several more names, including folk ones, but there are also those that can be found in the scientific literature, we will give them:
brown iron ore;
swamp ore;
hydrogoethite.
Composition of the mineral, properties of limonite
Limonite can be described with the following complex formula: FeO*OH*nH2O. In fact, it is an amorphous substance, the constant composition of which cannot be determined; it is always different. Therefore, this mineral is not an independent species. That is, this name refers to iron hydroxides that have been crystallized to varying degrees.
That is, these are brown iron ores, but their composition is quite difficult to determine; they do not have a stable composition. If you take a scientific description, you can get to know the breed in more detail. Some rocks are generally called hydrogels.
Characteristics of limonite
The mineral has a matte shine and a metallic sheen. It’s opaque. You may notice traces of brown paint, which are visible in the photo. Hardness – from 1 to 4 on the Mohs scale. Density approximately 3 g/cm3. There is no cleavage, it is not magnetic. Interestingly, the material acquires magnetic properties if it is heated for a long time at a certain temperature. It dissolves well in hydrochloric acid.
Sometimes specific stones are formed from the rock. They have a bizarre shape, red or brownish color. There are also deposits of limonite in Europe. Interestingly, one of the largest deposits is located in tiny Luxembourg. In addition, they note that the ore there is of very high quality. Of course, development there is being carried out at an accelerated pace, but still the scale of raw material extraction is not as high as we would like. The amount of ore has not been fully estimated, but Europeans have high hopes for this deposit.
Origin of limonite
Let’s try to determine the origin of limonite. The researchers came to the unanimous conclusion that the rock is formed as a result of weathering, but not ordinary, but chemical. Moreover, minerals that contain a lot of iron are eroded:
pyrite;
siderite;
chalcopyrite;
magnetite.
The mineral limonite is formed during the deposition of hydrogenated iron compounds at the bottom of reservoirs, most often swamps. In this case, it is called swamp ore. If at the bottom of the lake, then lake ore. There are cases where deposits occur in seawater, but for this to happen the depth must be shallow.
Of course, glandular bacteria have a direct and direct influence in this process. But getting into the deeper layers of the earth, limonite heats up and degenerates into other minerals, becoming hematite and magnetite.
Varieties of limonite
Limonite has varieties. One of them has a rather original name – brown glass head. In fact, it is a rather simple mineral, nothing more than sintered rounded shapes. They got this name due to the fact that their surface is smooth and shiny, so you can compare it to the head, and it is brown because it has the corresponding color.
Another variety of limonite is yellow ocher. Otherwise it is called iron. It is actively used by artists to obtain paints. Based on this ocher, many colors are obtained; it is even added to dark paints to obtain shades. Initially it looks like a yellow or orange powder. It’s soft.
Crystals have many faces,
Shine, inclusions, transparency.
And excite the inquisitive mind
Color and shape ambiguity.Sophisticated Observer
He will discern the secrets of their lives,
And put it on shelves
Anything that seems random.
