This is as unique a collectible as you will find! The Highland Mint minted a Commemorative antique Bronze Coin of New Busch Stadium and through a special process designed a cavity on the back to embed Dirt from the new stadiums infield! Each Infield dirt coin is labeled with an MLB Authentication hologram certifying that MLB security witnessed the dirt being put into each coin! Furthermore the Dirt was collected from the Busch Stadium infield under the auspices of MLB security as well! Each 39mm Coin is protected in an acrylic capsule to preserve its condition and presented in a 2.5" x 2.5" hinged jewelry box for display purposes or safekeeping. Furthermore each coin is accompanied by a certificate of authenticity.