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Not-So-Precious Metals

October 11, 2011

If you’re wearing a gold ring, it began as a meteeorite that struck the earth billions of years ago, but vast deposits of precious metals are also hidden deep in the earth’s core.

Transcript

BOB HIRSHON (host):

The birthplace of bling…I’m Bob Hirshon and this is Science Update.

Precious metals are considered valuable because they’re rare. But it’s all relative, according to geologist University of Bristol Matthias Willbold. He says the earth’s core is formed of iron, which sank along with vast amounts of metals like gold and platinum during the formation of the earth 4.5 billion years ago.

MATTHIAS WILLBOLD (University of Bristol):

If you would take out all the precious metals that are locked up in the earth’s core, you bring them up to the surface that would basically make up a four meter thick layer. So, you’re basically sitting on a treasure.

HIRSHON:

But Willbold says the precious metals stored in bank vaults or worn on fingers come from a different source. He and his colleagues analyzed ancient rocks from Greenland and concluded that the bling we’re most familiar with actually landed on earth when it was bombarded by meteorites as recently as 3.8 billion years ago. I’m Bob Hirshon for AAAS, the science society.