Question

Match List - I with List - II 

List - I	Optical / Mineral Property	List - II	Associated Condition
A. Cleavage	Splitting property	I	Plane polarized
B. Twinkling	Optical effect due to slight misorientation	II	Ordinary
C. Twinning	Crystal intergrowth phenomenon	III	Crossed nicols
D. Dispersion	Splitting of light into colors	IV	Convergent

• A. A-I, B-II, C-III, D-IV
• B. A-I, B-III, C-II, D-IV
• C. A-II, B-I, C-IV, D-III
• D. A-II, B-I, C-III, D-IV

Hint:

Cleavage is commonly seen in plane polarized light, while twinning is best observed under crossed nicols.

Answer 1

The Correct Option is A

Concept:
Different optical mineral properties are observed under different light conditions in a polarizing microscope.

Step 1: Match Cleavage.
Cleavage is commonly observed in plane polarized light. \[ A\rightarrow I \]

Step 2: Match Twinkling.
Twinkling is observed in ordinary light conditions in optical mineralogy. \[ B\rightarrow II \]

Step 3: Match Twinning.
Twinning is clearly observed under crossed nicols because different twin lamellae show different extinction positions. \[ C\rightarrow III \]

Step 4: Match Dispersion.
Dispersion is studied with convergent light in interference figures. \[ D\rightarrow IV \] Therefore, the correct matching is: \[ A-I,\ B-II,\ C-III,\ D-IV \] \[ \therefore \text{Correct Answer is (A)} \]