Kyanite is one of the rarest minerals and gemstones in nature, all due to its origin and formation related to very extreme high-pressure geological environments only found at convergent plate boundaries and collisions between continents.
These conditions have endowed it with unique properties and characteristics, and even people who believe in the metaphysical and energetic properties of crystals affirm that this stone can be compared to citrine.
What is kyanite?
The kyanite is a very resistant mineral and precious stone from the group of aluminum silicates, with the chemical formula Al2(SiO5), where 63.2% of its volume is Al2O3 and 36.8% corresponds to SiO2, which is characterized by presenting with an intense blue color and sometimes green.
It is basically a mineral that forms during the metamorphism of pelitic sedimentary rocks at high pressure that affects clay minerals.
This glass has several uses, for example it is used in the manufacture of refractory porcelain, ceramics and gems or precious stones.
Finally we can mention that kyanite is part of a group of polymorphic metamorphic minerals together with andalusite-chiastoliteand the sillimanite.
Kyanite stone meaning
Currently the kyanite stone It gives its owner a touch of elegance, credibility and sympathy.
In addition, this stone has always meant fidelity, serenity, constancy, trust and transparency. Therefore it is said that it improves communication, dissipates stress and helps enhance the capacity for logical thinking.
Regarding its spiritual meaning, it is believed that the kyanite stone It endows with a great stimulating energy that encourages perseverance and tranquility, thus managing to align the chakras within the body and achieve an energetic balance and spiritual guides.
In these properties the kyanite is very similar to citrine quartz, since it is thought that these stones do not accumulate or retain negative energies, so they do not need cleaning and rather are excellent for clarifying and cleaning other crystals.
Physical, chemical and characteristic properties
| kyanite | Physical, chemical and characteristic properties |
|---|---|
| class, group | Silicate, Nesosilicate |
| Brightness | Vitreous, pearly. |
| Color | Usually blue with dark hues in the center of the crystal. In some cases white, gray, green. |
| Stripe | White or colorless. |
| Chemical formula | Al2(SiO5) Aluminum silicate |
| Chemical composition | Al2O3=63.2%, SiO2=36.8% |
| polymorphs | Andalusite and sillimanite. |
| Mohs hardness | It has a hardness of 5, parallel to the length of the crystals and 6.5 to 7 at right angles to this direction. |
| Specific weight or density | 3.5 to 3.7 g/cm3 |
| Cleavage or exfoliation | Perfect cleavage in two directions, in some cases the faces are grooved |
| Fracture | Breakable or chipped |
| Tenacity | Fragile |
| crystalline system | triclinic |
| Way of introducing yourself (habit) | Long tabular crystals, rarely terminated. Also in leafy aggregates or sheet crystals and as masses of radiant crystals. |
| Origin or geological environment | It is formed during high pressure metamorphism of sedimentary rocks from clay minerals. |
| associated rocks | Gneiss, schist, pegmatite granite. |
| Associated minerals | Garnet, staurolite, corundum, quartz, almandine, biotite, albite, andalusite. |
| Applications | In ceramics, gems, spark plugs, refractory porcelain. |
The kyanite ore It comes in shades of blue, green, gray or white, has a vitreous luster and a white or colorless stripe.
It comprises a triclinic system, in addition to leafy, tabular habits, it has a disaggregatable or splintered fracture and shows brittle tenacity.
It has an unusual or variable hardness. If the hardness of the long lengths parallel to the glass is taken, it will have a hardness of 4.5 to 5, on the other hand, in the short dimension of the glass the hardness is 6.5 to 7.
Types of kyanite
High-quality gemstones are typically blue in color, ranging from light blue to dark blue. However, there are also light colors, green, black, rarely purple and can become pleochroic.
Green kyanite
Green kyanite is the same as an aluminum silicate that is formed by regional high-pressure metamorphism of clayey sediments, however its color is due to possible chromium impurities in its composition.
Regarding its meaning and magical properties, it is believed that it stimulates and opens the heart chakras.
Black kyanite
Black kyanite is very rare in nature just like the other types of kyanite crystals Its origin is high pressure metamorphic, however its color is mainly due to high amounts of iron in its chemical composition.
Regarding its magical properties, it is believed that it achieves a body-earth connection and helps align the chakras.
Origin, formation and geological environment.
It occurs mainly in metamorphic rocks. It is formed during high pressure metamorphism of sedimentary rocks from clay minerals.
In metamorphosed areas it is found in gneiss and schist and rarely in quartzite or eclogite. It is often associated with other metamorphic minerals such as staurolite, garnet, and corundum.
Polymorphs of the mineral kyanite
It is known that minerals kyanite, sillimanite and andalusite are polymorphs, they have the same chemical composition Al2(SiO5). Kyanite forms at high pressure, andalusite at low pressure, and sillimanite forms at high temperature.
Optical properties of kyanite crystal
In thin film, the kyanite crystal It has the following optical properties:
| Guy: | Biaxial (-) |
| Color: | pale blue or colorless |
| Form: | Long laminar prismatic crystals |
| Relief: | Tall |
| IR Values: | nα=1.712-1.718 nβ=1.720-1.725 nγ =1.727-1.734 |
| 2V: | Measured: 82° to 83° |
| Birefringence: | 0.015 |
| Extinction: | Variable from straight to 30° approximately |
| Dispersion: | weak rv |
| Pleochroism: | Weak |
| Interference Colors: | Moderate, red colors in the maximum. |
In this sample of gneiss, in natural light it is observed that the kyanite crystals are colorless, presenting a high relief, while in polarized light the interference colors have a reddish hue.
How to identify the kyanite stone?
This mineral can be identified by its blue color, because it presents leafy, tabular crystals with perfect cleavage in two directions and in some cases the crystal faces have striations.
An interesting characteristic of this mineral is its variable hardness, along the length of the crystal it has a hardness of 4.5 to 5 and across the width of the crystal its hardness ranges from 6.5 to 7.
Kyanite Stone Uses
Gems that are transparent and have a deep sapphire blue color are the most desired and popular, those that have a less intense color can be seen as a blue topaz or blue aquamarine.
Uses as a gemstone
It is considered an exotic jewel and very little known in typical jewelry stores. It is found in artisan jewelry stores or in jewelry stores that are related to mineral distributors.
High quality kyanites with pleasant colors can be used in jewelry such as rings, necklaces, earrings, pendants, chains, earrings, etc. Cabochons and faceted stones are also made that are attractive to the buyer.
It is a difficult mineral to cut due to its two hardnesses, therefore, an expert is required to cut these stones.
Due to its striking colors, hardness, and resistance to wear, kyanite is often widely used in the jewelry industry and other industrial uses, which means that it enters the group of precious stones, and for this reason it is often called a kyanite stone.
This mineral is highly appreciated in jewelry for its high hardness and striking colors, in addition, its price is low compared to other high-value gems such as the sapphire stone.
This mineral is usually associated with blue schists, these rocks are very striking to the naked eye and are appreciated by collectors and also used as ornamental rocks, where kyanite is the star ornamental stone.
Industrial uses of kyanite stone
This stone has several industrial uses:
- For the manufacture of refractory products such as mortars, bricks, furnace furniture, resistant to very high temperatures.
- To make molds that are used to melt metals at high temperatures.
- In products of the automotive and railway industries, due to its resistance to heat.
- In the manufacture of mullites, which is used to make brake shoes and clutch linings.
- It is used to make highly resistant refractory porcelains, which are suitable