Group I | Group II |
P. Sillimanite | 1. First order |
Q. Quartz | 2. Second order |
R. Muscovite | 3. Greater than third order |
S. Calcite | 4. Third order variegated |
The interference color of minerals depends on their optical properties and thickness. For a standard thickness of 0.03 mm, the highest order of interference colors for the given minerals is as follows:
The correct sequence is:
\[ \mathbf{P - 2^{nd}, \quad Q - 1^{st}, \quad R > 3^{rd}, \quad S - 3^{rd}} \]
Hence, the correct matching follows: P - 2nd, Q - 1st, R > 3rd, S - 3rd.