Hematite is a mineral from the group of oxides, it is a ferric oxide whose chemical formula is Fe2O3, where 70% of the volume is Fe and 30% is O2, it has its genesis in sedimentary environments, crystallization during the differentiation of magma, precipitation of hydrothermal fluids, contact metamorphism and its use is widespread as the main iron ore.
Properties and characteristics of the mineral
| hematite | Physical properties and characteristics |
|---|---|
| Class | Rust (Ferric Oxide) |
| Brightness | Metallic, sub-metallic, earthy. |
| Color | Reddish brown to black |
| Stripe | red |
| Chemical formula | Fe2O3 |
| Chemical composition | Fe=70%, O=30% |
| Hardness | 5.5 to 6.5 |
| Specific weight or density | 5.26 g/cm3 |
| Tenacity | Fragile |
| Cleavage or exfoliation | None, however, on some occasions exhibits rhombohedral and basal parting. |
| Fracture | Unequal |
| crystalline system | Hexagonal |
| Way of introducing yourself (habit) | Massive, micaceous, botryoidal, crystalline, oolitic, fibrous and others. |
| Origin or geological environment | Crystallization during magma differentiation, precipitation of hydrothermal fluids, contact metamorphism, and sedimentary environments. |
| associated rocks | Igneous (granite), sedimentary (shale, cherts, iron in strata and bands), metamorphic. |
| Associated minerals | Biotite, chlorite, magnetite, quartz, calcite, albite, barite, pyrite, magnesite. |
| Applications | Major iron ore, pigment, polishing powder, red ochre, radiation shielding, heavy metal separation. |
The hematite It is one of the minerals found in the earth’s crust and surface of the Earth. They are found in sedimentary, metamorphic, and igneous rocks in areas around the world.
Its importance is due to the fact that it is the most important mineral of iron. It was extracted in many parts of the world. At present its extraction is limited, coming from a few dozen large deposits.
This mineral is reddish-brown to black in color, the luster can vary from metallic to submetallic or earthy, and is recognizable by the red streak color. “Red ochre” is the red earthy variety.
It has different forms, it can be found massive, botryoidal, crystalline, oolitic, fibrous, micaceous among others. It does not present cleavage, however, it usually exhibits rhombohedrons and presents an unequal fracture.
Mentioning other physical properties, the hardness is 5.5 to 6.5 on the Mohs scale, with a specific weight of 5.26 g/cm3.
Meaning and esoteric properties of the hematite stone
The hematite within the esoteric field It is one of the most famous and therefore a number of meanings and healing and magical properties have been attributed to it, but it must be made clear that none of these properties has scientific verification.
Thus, hematite is believed to be a very powerful protective stone that dispels negativity and prevents negative vibrations from reaching our personal energy field (Aura). Therefore having a very positive vibration, increases our energy, increases our confidence and reduces shyness.
This stone is also thought to awaken self-love, strengthen our courage and determination, and reduce shyness.
Finally, it is believed that recharges our energy, stimulates concentration, helps to overcome addictions, balances the appetite and prevents negative energies from adhering to the Aura.
Origin, formation and geological environment.
The hematite it can form in the precipitation of hydrothermal fluids that move through rocks or from crystallization during magma differentiation.
It can originate as a product of sublimation with volcanic activities, as an accessory mineral in feldspathic igneous rocks (granite).
A variety of alteration is present as specular hematite in vugs or matrix, veins, and as a magnetite replacement. It is an alteration mineral in many systems related to intrusion.
It can often occur in veins, produced by diorite or granodiorite intrusions, as hematite is a common alteration mineral in many intrusion-related systems.
In epithermal settings, hematite may be important in vuggy quartz in high-sulfidation systems, or low-sulfidation when associated with chlorite alterations.
They can also originate during contact metamorphism when magmas react with adjacent rocks. In regional metamorphism, as alteration of limonite, siderite or magnetite.
Hematite and iron deposits
Large and important deposits of hematite They formed in sedimentary environments. According to research 2.4 billion years ago, the planet’s oceans contained a large amount of dissolved iron and little free oxygen. Species such as cyanobacteria carried out photosynthesis, using sunlight to transform water and carbon dioxide into oxygen, carbohydrates and water, as a result they released the first free oxygen into the ocean environment. The released oxygen combined with iron to form hematite, this mineral sank to the seabed and gave rise to banded iron formations.
This process of photosynthesis was occurring in many places in the planet’s oceans and lasted hundreds of thousands of years, from approximately 2.4 to 1.8 million years ago, which allowed extensive hematite deposits to accumulate on the ocean floor of hundreds to several thousand. feet across that continue laterally for hundreds to thousands of square miles. This event is in the Earth’s rock record as one of the largest rock formations.
A variety of sedimentary iron deposits contain magnetite, hematite or other iron ores.
Oolitic hematite has a reddish-brown color, earthy luster, and is composed of small round grains.
Hematite in thin film
The optical properties to recognize hematite are:
- Color: Usually dull, however can be deep reddish brown
- Interference colors: they are very high colors, but they are masked by red-brown colors.
- Anisotropism: Strong.
It is recognized in a thin section by its dark red color in transmitted light, strong anisotropism, and internal reflections in reflected light. Secondary replacement and interlinking with magnetite at grain boundaries and fractures are common.
How to identify the mineral Hematite?
Despite the forms that this mineral occurs in the field, reddish brown to black, this mineral is identifiable by its red stripe color (Indian red) which is the most important characteristic for identification and distinction from other minerals.
Also, some of these minerals respond to magnetism, it is observed that they are attracted to a common magnet. The reason for this is because specimens of hematite contain magnetites to cause this attraction.
The weak attraction for the common magnet can be confused with other minerals such as magnetite or pyrrhotite. To discard these two minerals, the key is the red stripe that the mineral presents.
In the event that the sample shows strong magnetism and a red stripe color, we would be talking about a combination of hematite and magnetite.
When the hematite specular is thick, sheets of this mineral may be interlinked with other minerals in the veins.
Specular Hematite or Micaceous Hematite
It has the appearance of being a silvery rock composed of flakes of shiny micas, but no, they are flakes of hematite and the reddish streak is the key to their distinction. Hardness in this case does not help, because the sample tends to crumble.
Hematite uses
- Main iron ore, because it is more abundant and deposits are found in many places on the planet, unlike magnetite, which contains more iron, but is not as abundant.
- Manufacture of pigments, continues as one of the most important pigmented minerals.
- Silver colored hematite with a solid texture is used as a minor gemstone to produce small sculptures, cabochons, and the brilliant luster and weighty feel makes it a popular tumbled stone.
- The density and low cost of hematite serve as ballast for ships and stop x-rays.
- Preparation to separate heavy metals.
- As a protector in solar radiation.
- Laser.
- When ground, the fine powder plus water forms a liquid with a very high density.
Hematite on the planet Mars
NASA research discovered that this mineral is one of the most abundant on the planet Mars, it is found in rocks and on the planet’s surfaces. This is why the planet has a reddish-brown landscape and appears red in space.