Coarsen
/ˈkɔːrsn/
Definition 1 of 2
Pro Tip 1/3Physical Change
Use 'coarsen' to describe a change in texture, often making it less smooth. 
Washing dishes without gloves can coarsen your hands.
Pro Tip 2/3Natural Process
Highlight the process of natural wear or aging when using 'coarsen'. 
The stone steps had coarsened with the passage of time.
Pro Tip 3/3Negative Context
Consider that 'coarsen' often implies a decline in quality or appeal. 
Overuse diminished the charm of the carpet, the pattern coarsening with each tread.