This is an extremely delicate pot that has been bisque fired and then smoke fired to produce the random patterns. This one also has some ghost-like images of grasses, added with a resist before smoke firing.
 
Like all smoke fired pots, this isn't fully vitrified (which just means it has been fired to a relatively low temperature and is still a little porous). It just means that it can't hold water without a bit of seepage, which would likely also ruin the smoke effect. Best displayed as it is or with dried flowers.