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.

The more expensive one is usually the type of marble that's exported. Last year, 1.2 million tons of blocks crossed the Italian border to China, the United States, and Germany as the top 3.

Rome has uncovered the four large marble maps illustrating its evolution and expansion, from its foundation to the apex of its empire, hanging on the Via dei Fori, in front of the Colosseum, which had ...

The more expensive one is usually the type of marble that's exported. Last year, 1.2 million tons of blocks crossed the Italian border to China, the United States, and Germany as the top 3.