Burro, a "ghost" style leather from Conceria Walpier in Italy, is simply mind blowing stuff.  Those who love the patina / visible journey / patina aspect of vegetable tanned leathers can expect to have a special appreciation for this leather especially after holding and using it.
Some leathers naturally exhibit a beautiful bloom after a certain period of inactivity, which is usually easy to wipe or wear away.  Burro, however, is coated in a thin but dense layer of wax/tallow that can take several days, weeks, or months to fade depending on how it is being used.