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The answer Is feldspar
it is a rock-forming mineral which has particular importance in the glass and ceramics industries since it works as a fluxing agent. This means that feldspar reduces the melting temperature of quartz, consequently helping to control the viscosity of glass. Moreover, this rock-forming mineral is one of the most common minerals in existence, forming approximately 60% of earth’s terrestrial rocks. Finally, each year about 600,000 tons of feldspar is mined in the United States from quarries in South Dakota, Oklahoma, Virginia, California, North Carolina, and Idaho. Besides this, vast deposits of felspar exist throughout the world, but the greatest challenge remains extracting and transporting the minerals to the point of consumption.
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