Granite:

* Composition: Mainly composed of quartz, feldspar, and mica. These minerals are very resistant to weathering and erosion.

* Structure: Has a coarse-grained, interlocking texture, making it very strong and durable.

* Weathering: Granite weathers slowly, primarily through physical processes like frost wedging and abrasion. Chemical weathering is less significant due to the resistance of its minerals.

* Erosion: Granite erodes slowly, forming landforms like mountains, cliffs, and boulders.

Limestone:

* Composition: Primarily composed of calcium carbonate, a mineral that is readily soluble in acidic water.

* Structure: Can be crystalline or porous, making it susceptible to chemical weathering.

* Weathering: Limestone weathers rapidly, especially in areas with acidic rainfall or groundwater. It dissolves and breaks down into smaller particles.

* Erosion: Limestone erodes quickly, forming landforms like caves, sinkholes, and karst topography.

Key Differences:

1. Mineral Composition: Granite's resistant minerals make it less susceptible to chemical weathering compared to limestone's soluble calcium carbonate.

2. Structure: Granite's interlocking texture provides strength and durability, while limestone's porosity allows for faster chemical breakdown.

3. Weathering Processes: Granite weathers primarily physically, while limestone undergoes significant chemical weathering.

In summary, granite's composition and structure make it much more resistant to weathering and erosion than limestone. This leads to slower changes in granite compared to the rapid transformation of limestone over time.