Feldspar is a group of rock-forming tectosilicate minerals which make up over 50% of the Earth's crust. Feldspars are aluminosilicate minerals which crystallize from magma as veins or grains in igneous rocks or form from solidified lava. They are also present in many types of metamorphic rock. Feldspars are also very important industrial minerals used in many applications from glassmaking and ceramics to fillers and abrasives.

Properties and Composition
Feldspars are aluminosilicate minerals containing sodium, potassium, calcium or barium. The different cations give rise to the name of the feldspar mineral species. The most common feldspar minerals are:
- Orthoclase - KAlSi3O8 - Contains potassium
- Microcline - KAlSi3O8 - Contains potassium
- Plagioclase - (Na,Ca)Al(Si,Al)Si2O8 - Contains sodium and calcium
- Sanidine - KAlSi3O8 - Contains potassium
Feldspars have an earthy to dull luster and are gray, pink to white in color. Their hardness ranges from 6 to 6.5 on Mohs scale. They are not very hard materials but have good thermal stability and resistance to weathering, making them desirable for industrial applications.

Uses of Feldspar
- Glassmaking
Feldspar, especially sodium-rich plagioclase, is the primary constituent of glass, comprising up to 60% by weight. Feldspar helps with glass viscosity, durability and imparts refractory properties.
- Ceramics and Pottery
Around 30% of mined feldspar is used in production of ceramics, pottery, sanitaryware, electrical goods, abrasives, engobes and glazes. Feldspar increases fusibility and improves physical properties of finished ceramic products.
- Fillers and Extenders
As an extremely inexpensive yet highly versatile mineral, feldspar finds a number of applications as a filler or extender. It is used in paints, coatings, rubber, plastics, resins, sealants, mastics, putties and other products.
- Abrasives
Harder potassium feldspars varieties like orthoclase and microcline are used as abrasive powders for scouring pads, scrubbing bubbles, sandpaper, polishing compounds and other applications.

Global and Domestic Production
The global production of feldspar in 2019 was estimated to be around 8.5 million tonnes with China, Italy, Turkey and United States being the leading producers. India hosts large deposits of feldspar especially in the states of Rajasthan, Tamil Nadu, Andhra Pradesh and Odisha. India produced around 3 million tonnes of feldspar in 2019 and is one of the leading exporters. However, there is immense scope for expanding domestic mining and value addition operations to fully leverage the potential of India's feldspar reserves.

Feldspar Mining in India
- Rajasthan
The state of Rajasthan has over 50% of India's total feldspar reserves concentrated in Jodhpur, Pali, Barmer and Jalore districts. Open cast manual mining is prevalent and Handicraft Corporation of India runs operations.
- Tamil Nadu
Madurai, Salem, Dharmapuri and Tiruvannamalai districts hold large deposits. Thirukalukundram and Tiruvannamalai deposits are the largest in Tamil Nadu. Mining Methods include both open cast mining and underground mining.
- Andhra Pradesh
Cuddapah and Nellore districts in Rayalaseema and coastal AP regions have significant placer deposits. Mechanized open cast mining is the predominant method.
- Odisha
Koraput, Kalahandi, Nabrangpur are the Feldspar bearing districts in Odisha. Remada Ghati range extends feldspar reserves.

Feldspar has wide industrial applications and India holds substantial reserves of this important industrial mineral. However, there is need to ramp up exploration, mining and value addition activities to fully capture potential economic benefits. Development of beneficiation and processing industries can generate large scale local employment. With growing global demand, feldspar is projected to remain a strategic industrial mineral for India.

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