Each geode measures approximately 0.50 to 0.60 inch in diameter - a great size for dollhouses, to cut for jewelry, or for those looking for the most geodes for their money. However, due to the small size, these geodes are sorted mine-run, meaning we cannot determine the number of hollows but typically, on average, somewhere between 40-80% are hollow but NO guaranteed hollow percentage with these geodes! Most orders will ship Priority mail (either regular or in a flat rate box).