Question

Arrange the following minerals in terms of increasing stability
(A) Biotite
(B) Quartz
(C) Hornblende
(D) Muscovite
Choose the correct answer from the options given below :

• A. (A), (B), (C), (D).
• B. (B), (C), (A), (D).
• C. (C), (A), (B), (D).
• D. (C), (A), (D), (B).

Hint:

Quartz is the most stable and resistant primary mineral.
As a result, most sand grains in highly weathered soils consist almost entirely of quartz.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
The stability of primary silicate minerals against chemical weathering is defined by Goldich's Weathering Series.
Goldich's series is the reverse of Bowen's Reaction Series: minerals that crystallize first at high temperatures and pressures are the least stable at the Earth's surface, while minerals that crystallize last at lower temperatures are the most stable.

Step 3: Detailed Explanation:
Let us list the common primary minerals in order of their susceptibility to chemical weathering (from least stable to most stable):
\[ \text{Olivine} < \text{Pyroxene (Augite)} < \text{Amphibole (Hornblende)} < \text{Biotite} < \text{Orthoclase} < \text{Muscovite} < \text{Quartz} \]
Let us evaluate the four minerals given in the question:
1. (C) Hornblende:
As an amphibole, it has a double-chain silicate structure, making it highly susceptible to weathering.
This is the least stable mineral among the four.
2. (A) Biotite:
This is a dark mica with a sheet-like structure containing magnesium and iron.
It is slightly more stable than hornblende.
3. (D) Muscovite:
This is a light-colored potassium mica.
Because it lacks iron and magnesium, it is highly resistant to chemical weathering.
4. (B) Quartz:
This has a highly stable, three-dimensional framework of silicon-oxygen tetrahedra ($\text{SiO}_2$).
It is extremely resistant to chemical weathering, making it the most stable mineral.
Arranging them in order of increasing stability (least stable to most stable):
(C) Hornblende $\rightarrow$ (A) Biotite $\rightarrow$ (D) Muscovite $\rightarrow$ (B) Quartz.

Step 4: Final Answer:
The correct sequence of increasing stability is (C), (A), (D), (B).
This matches Option (D).