Given below are two statements:
Statement I: The copper ores of the Khetri-Singhana region of Rajasthan also contain minor amounts of gold.
Statement II: Sillimanite is used for making furnaces in glass industry.

Correct option is A

The correct answer is The correct answer is (a) Both Statement I and Statement II are true 
Explanation:
. Statement I is true; studies have confirmed the occurrence of native gold and silver in the copper ores of the Khetri-Kolihan region (part of the Khetri-Singhana belt) in Rajasthan, albeit in minor or trace amounts (around 0.3 to 0.5 g/t).
. Statement II is true; sillimanite is a high-grade aluminosilicate mineral valued for its refractory properties, such as resistance to high temperatures, chemical corrosion by molten slag and glass, and low thermal expansion.
. It is a crucial raw material for manufacturing high-performance refractory products, including bricks for steel and glass melting furnaces. 
Information Booster:
. The Khetri copper belt is an 80 km long metallogenic province and is the largest copper ore repository in India.
. Sillimanite, along with kyanite and andalusite, belongs to the sillimanite group of minerals which are known as "super-refractories".
. Upon heating, these minerals convert to mullite and vitreous silica, which provides excellent high-temperature stability and resistance to thermal shock and corrosion, making them ideal for the harsh environment of a glass furnace.