Draw on rocks with coal

Summary
Rocks are able to be drawn on with coal.

Core concept
Getting out of the mines is a trial for those less direction oriented, and when teleporting instead of running. Drawing on the sandstones or rocks to mark w/ arrows or mark that you’ve been there would be a great way to keep track during one trip. Drawings could time out as well. They wouldn’t have to be permanent. But available for the current run.