Question

Match the minerals in Group I with their optical properties in Group II

Group I		Group II
P	Sodalite	1	Mottled extinction
Q	Tourmaline	2	Isotropic
R	Calcite	3	Pleochroic from blue to brown
S	Muscovite	4	Twinkling effect

• A. P-4, Q-3, R-2, S-1
• B. P-2, Q-3, R-4, S-1
• C. P-3, Q-1, R-2, S-4
• D. P-1, Q-3, R-4, S-2

Answer 1

The Correct Option is B

The question requires us to match minerals from Group I with their corresponding optical properties from Group II. Let's analyze each mineral and its optical property:

1. Sodalite: Sodalite is an isotropic mineral. This means that its optical property does not change with orientation. Hence, it matches with option 2: Isotropic.
2. Tourmaline: This mineral is known for its pleochroism, where it appears to change color when observed from different angles under polarized light. Specifically, tourmaline can be pleochroic from blue to brown. Hence, it matches with option 3: Pleochroic from blue to brown.
3. Calcite: Calcite is recognized for its twinkling effect, which is noticeable due to its double refraction properties. Therefore, it matches with option 4: Twinkling effect.
4. Muscovite: This mineral exhibits a characteristic mottled extinction when observed under cross-polarized light in a thin section. Thus, it matches with option 1: Mottled extinction.

Based on this analysis, the correct answer is:

• P - 2 (Sodalite - Isotropic)
• Q - 3 (Tourmaline - Pleochroic from blue to brown)
• R - 4 (Calcite - Twinkling effect)
• S - 1 (Muscovite - Mottled extinction)

Thus, the correct option is:

P-2, Q-3, R-4, S-1