Chemical Weathering Mineral Stability Order
Chemical weathering involves the breakdown of minerals through chemical reactions. The stability of a mineral during this process depends on its internal atomic structure and chemical composition. Minerals with stronger chemical bonds and simpler structures are generally more resistant to weathering.
Mineral Stability Ranking
The general order of decreasing stability (from most resistant to least resistant) for common rock-forming minerals during chemical weathering is:
- Quartz: Highly stable due to strong Si-O bonds.
- Feldspar: Less stable than quartz, but relatively resistant.
- Mica (e.g., Biotite, Muscovite): Intermediate stability.
- Amphibole & Pyroxene: More susceptible to weathering than feldspar.
- Olivine: Least stable among these common minerals, breaks down relatively quickly.
Determining the Correct Order
The question asks for the order of decreasing stability. Based on the established mineral stability ranking:
- Quartz is the most stable.
- Feldspar is the next most stable.
- Pyroxene is less stable than feldspar.
- Olivine is the least stable among the group presented in the options.
Therefore, the correct sequence of decreasing stability is quartz, feldspar, pyroxene, olivine.
This corresponds to the first option provided.
Important Questions from Weathering
- Bauxite formation is an example of metal enrichment by extreme
- Silcretes or silica-rich duricrusts generally form under
During normal weathering of a granite rock (A), clay minerals and then residue of gibbsite are formed. Which one is the correct weathering path for the rock in the given diagram ($\text{Al}_2\text{O}_3$, $\text{CaO}$, $\text{Na}_2\text{O}$ and $\text{K}_2\text{O}$ are in moles).
- During spheroidal weathering, a block of rock converts to a spheroid due to
- Which type(s) of chemical reactions occur(s) during the weathering of pyroxene?
