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TITLE: All Rocks Contain Water

There are about 9,000 aggregate operations in the U.S., putting one close to every major city. We use about 3 billion tons of crushed stone, sand, and gravel every year—nearly half the Earth materials mined in this country. Today, the concrete foundations and facades of homes, schools, offices, and stores are built with quarried materials. An average new house in the U.S. is constructed with about 400 tons of sand, gravel, and crushed stone (mostly limestone).

  • Anatomy of a Road

    Video Transcript
    Woman: “Every man woman and child uses about 10 tons of it each year.”

    Man: “You’re joking? Ten tons…of rocks? How is that even remotely possible?”

    Woman: “Well, for starters, each lane of this interstate consumes an astonishing 38,000 tons of rock per mile. Your average pick up truck carries about a ton. That’s 38,000 pick up trucks of rock that are used to make each mile of highway. The average home uses 400 tons of gravel and concrete.”

    Man: “Millions of tons of stone are used in farming each year as lime.”

    Woman: “Or in toothpaste, glass, runways, railroad beds or pharmaceuticals. It’s all aggregate.”

    Man: “What’s an ’aggregate’?”

    Woman: “It’s this…rock in all its forms; sand, gravel and crushed stone, like granite and limestone.”

    Man: “Where do they get it all from? I mean do they just dig it up somewhere?”

    Woman: “That’s exactly what they do - dig it up. More accurately, some of it is mined and some is dredged from under water and from other areas where there are sand and gravel deposits. And for some, they have to blow it up. It’s actually a series of small, precisely set and tightly controlled mini-blasts just microseconds apart. Fracturing rock is a very precise, exacting science. The result is a highly regulated and controlled fracturing process. The actual noise or vibration is carefully monitored. And is usually less than the noise of a highway.”

  • [Photo: Quarry]

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    Smithsonian National Museum of Natural History Department of Mineral Sciences website Credits