How does the granular composition of granite impact its weathering resistance?

Granite, a common igneous rock, exhibits varying degrees of weathering resistance depending on its granular composition. The size, arrangement, and mineralogy of its grains play a crucial role in determining its durability.

1. Mineral Grain Size: Coarse-grained granite tends to weather faster than fine-grained varieties due to larger surface areas exposed to environmental factors like water and temperature fluctuations.

2. Quartz Content: Granite with higher quartz content resists weathering better because quartz is highly resistant to chemical and physical breakdown.

3. Feldspar and Mica: These minerals are more susceptible to hydrolysis and oxidation, weakening the rock's structure over time.

4. Interlocking Grain Structure: Tightly interlocked grains enhance mechanical strength, reducing susceptibility to cracking and erosion.

5. Environmental Exposure: Even durable granite degrades under prolonged exposure to acidic rain, freeze-thaw cycles, or biological activity.

Understanding these factors helps geologists and engineers assess granite's suitability for construction and preservation efforts.