The mint condition, perfect 10 Mickey Mantle card.

Courtesy of History Colorado

Next week, an armored truck will transport a small piece of cardboard worth millions of dollars from a secret vault to the History Colorado museum. That slice of cardboard is the “Holy Grail” of baseball cards. It's from 1952, featuring legendary Yankees center fielder Mickey Mantle. It'll be on display for three days at the "Play Ball" exhibit alongside other items from baseball history, such as Joe DiMaggio’s uniform and a baseball used during the first Rockies game.

The Mantle card and other items come from the prodigious collection of private collector and Denverite Marshall Fogel. He talked to Colorado Matters about what makes the card so valuable. It's in mint condition and has a perfect PSA 10 rating. I'll only be shown for three days, July 16-18, because of concerns about UV damage.