Kyanite
Kyanite is a blue to greenish-blue mineral, typically found in metamorphic rocks that are rich in aluminium.
➡️ Geological Nature:
- It is classified as an aluminium silicate mineral.
- It forms under high-pressure, low-temperature conditions, especially during the metamorphism of clay-rich sedimentary rocks.
Key Physical and Industrial Properties
| Property | Details |
|---|---|
| High Refractoriness | Can withstand extremely high temperatures without deforming or breaking. |
| Aluminium Content | The higher the aluminium, the better the quality of kyanite — making it valuable for high-tech industrial uses. |
| Thermal Stability | Unlike many minerals, kyanite expands when heated (unusual behavior, but useful in controlled refractory applications). |
Applications of Kyanite
Kyanite is not a decorative gem — it’s an industrial workhorse.
| Sector | Application |
|---|---|
| Metallurgical Industry | Used to line blast furnaces and foundry molds. |
| Ceramics and Glass | Incorporated into ceramic bodies to improve thermal shock resistance. |
| Cement Industry | Used in kiln linings and other high-temperature zones. |
| Automobile Sector | Spark plugs — due to high dielectric strength and heat resistance. |
Global Distribution of Kyanite
| Country | Status |
|---|---|
| USA | Top producer and consumer — especially in Virginia and Georgia. |
| India | Second most important producer globally. |
| Others | Limited production globally, but andalusite (a related mineral) is found in South Africa, France, and China. |
🧠 Kyanite, andalusite, and sillimanite are polymorphs — they have the same chemical composition (Al₂SiO₅) but different crystal structures, forming under different pressure-temperature conditions.
Kyanite in India: Reserves and Production
✅ Reserves (2020):
105.68 million tonnes
| State | Share of Resources |
| Telangana | 45.75% |
| Andhra Pradesh | 30.28% |
| Karnataka | 12.46% |
| Jharkhand | 7.22% |
Telangana and Andhra Pradesh hold nearly 76% of total Indian reserves.
✅ Production (2022–23):
- The production of kyanite at 2,765 tonnes in 2022-23, decreased by 70.33% as compared to the previous year 2021-22
- Major Producers:
- Jharkhand (especially Singhbhum district) – accounts for ~80% of national output
- Maharashtra and Karnataka follow.
International Trade: Kyanite Exports & Imports (2022-23)
| Category | Details |
|---|---|
| Exports | India exports kyanite primarily to Turkey(38%), Greece(24%) and France(18%) |
| Imports | India imports kyanite — and sometimes its substitutes — from USA(94%) and China(6%), possibly for specific industrial grades or applications not available domestically. |