Thinking about art and geology, one of the ways I most often use art and design is in the creation of diagrams and sketches for my students to organize information.
Based on Andrew Alden's suggestions, I revised the rock cycle diagram I use in my intro geology lectures. I included a few extra graphic elements to imply some of the physical appearance or fabric of the rocks themselves:
My metamorphic rock icon looks like bacon... mmm, bacon.
I've also been working on making easy-to reproduce, simplified representations of tectonic boundaries. Real tectonic plate boundaries are very complex places, with lots of things going on. And at scale, they don't look like much, so I tend to hyper-exaggerate the proportions to make the interpretations easier.