The Agates of North America Playing Cards are the best looking deck of cards ever. There’s nothing like the incomparable beauty of an Agate. This gorgeous deck features real photos of 52 Agates found in North America, including the Lake Superior Agate, Fairburn Agate, Fire Agate (absolutely stunning) and more! Anyone who appreciates rocks and minerals will love having these playing cards for their favorite games and for quick I.D. What’s an Agate? An Agate is a semi-precious stone of the cryptocrystalline variety of silica, chiefly chalcedony, characterized by its fineness of grain and brightness of color often with concentric bands that vary in color. Each Agate is unique. Agates form as deposits of minerals fill voids in rock (vesicles) over time (eons). All you really need to know is that they are beautiful.