And calacatta is one of the world's most expensive types of marble. It's more than double the price of carrara marble, yet mined in the same mountains. But the key to calacatta's price is its rarity.

Using an antique to wedge open a door is insane enough, but for it to be valued in the millions is just bonkers.

Natural marble brings unique colors and distinctive patterns to countertops. At an average cost of $70 per square foot, ...