Remember: only letter "A" is unlocked by default. There is an inapp purchase to unlock all the other sections at once (letters, objects, aniamls, shapes etc). "Very helpful app!" - Jay Bone "Amazing - This app has been incredibly useful in identifying silver hallmarks for my vintage jewelry business !!!" - Smithwestalandvc This is the ultimate guide to recognize the marks that identify any piece of valuable metal (silver, gold etc). There are over 17000 images all conveniently catalogued in categories to make your research even easier.