Question

Consider the following statements regarding Quartz: Which of the statements above are correct?

1. It is a soft mineral that dissolves easily in water.
2. It is a main component of granite.
3. It is used in the industrial manufacture of radars.

• A. All
• B. ii, iii
• C. iii only
• D. None of these

Answer 1

Answer:

B. ii, iii

• Quartz is a hard, crystalline mineral composed of silicon and oxygen atoms (silicon dioxide, SiO₂). It ranks second only to feldspar as the most abundant mineral in the Earth's continental crust.
• Statement 1 is incorrect: Quartz is a hard mineral, rating 7 on the Mohs hardness scale. It is insoluble in water and most acids.
• Statement 2 is correct: Quartz is a primary constituent of many igneous rocks, including granite, which is a common intrusive igneous rock. It also occurs in metamorphic rocks like gneiss and schist, and in sedimentary rocks such as sandstone.
• Statement 3 is correct: Due to its piezoelectric properties (generating an electric charge in response to applied mechanical stress), quartz is extensively used in the manufacture of electronic components, including oscillators for radios and radars. Its stability and precision make it ideal for these applications.
• Piezoelectricity in quartz was first discovered by brothers Pierre and Jacques Curie in 1880.
• Large-scale production of synthetic quartz crystals is crucial for meeting the demand in the electronics industry.