Can you sharpen a knife on Terracotta? In this video I find out. This is the second video in my series called, 'can you sharpen on it?' Where I experiment with lots of different mediums or sharpening stone alternatives that may work for sharpening a knife on.
Learning to use these different things would be a great survival skill to add to your repertoire. Not to mention it is a fun way to improve you sharpening skills.