On Earth we know of frozen carbon dioxide as "dry ice." If shaved, it could exist as "dry ice snow." On Mars the dry ice snow could precipitate, then become compressed into dry ice. It would probably be a stiffly packed granular solid.
I had only heard of "water ice" on Mars. Check the article on kottke.org Link: https://kottke.org/18/12/a-massive-ice-filled-crater-on-mars