Several years ago, Walter Luhrman, a metallurgist in southern
Ohio, discovered a copper deposit of tantalizing richness. North
America’s largest copper mine—a vast open-pit complex in
Arizona—usually has to process a ton of ore in order to produce
ten pounds of pure copper; Luhrman’s mine, by contrast, yielded
the same ten pounds from just thirty or forty pounds of ore.
Luhrman operated profitably until mid-December, 2006, when the
federal government shut him down. The copper deposit that
Luhrman worked wasn’t in the ground; it was in the storage
vaults of Federal Reserve banks, and, indirectly, in the piggy
banks, coffee cans, automobile ashtrays, and living-room
upholstery of ordinary Americans. A penny minted before 1982 is
ninety-five per cent copper—which, at recent prices, is
approximately two and a half cents’ worth. Luhrman, who had
previously owned a company that refined gold and silver, devised
a method of rapidly separating pre-1982 pennies from more recent
ones, which are ninety-seven and a half p