Which of the following is an insoluble amphibole mineral used in highway construction and as railroad ballast?

Correct option is D

The correct answer is (D) Hornblende.
Explanation:
· Hornblende is an insoluble amphibole mineral commonly used in highway construction and as railroad ballast due to its durability and resistance to weathering. It is a complex silicate mineral that contains calcium, magnesium, iron, and aluminum.
Key Points:
1. Hornblende Characteristics:
· A dark, dense mineral belonging to the amphibole group.
· Known for its strength and weather resistance, making it suitable for construction applications.
2. Applications:
· Used as aggregate in road construction.
· Ideal for railroad ballast, which supports train tracks and distributes weight.
3. Other Uses:
· Occasionally used in the production of concrete and asphalt.
Explanation of Other Options:
· Shale: A sedimentary rock, unsuitable for highway construction or ballast as it is fragile and not durable.
· Olivine: A silicate mineral, often used as a refractory material, but not suitable for highway construction.
· Gyserite: A siliceous sedimentary rock found in geysers, not used in construction.