That sandstone again, and "very sophisticated soot." I wrote: "If somehow people did want to buy sandstone at the price of gold, it must be because they have found some amazing quality to standstone that inspires them to buy it." Consider this, from the Washington Post:

The blue column contains a weird new furnace, of sorts, evidently the largest of its kind in the world. The furnace makes fluffy black stuff that "looks like soot," said Bob G. Gower, head of the company building the device. "But it's very sophisticated soot."

Indeed it is: Right now it sells for 39 times the price of gold. The black stuff consists of exceedingly small tubes of carbon, "the strongest thing you'll ever make out of anything in the universe," said Richard E. Smalley, the scientist who won a Nobel Prize for helping to discover similar objects.

Someday, when the price falls and the quality improves, this black stuff might be woven into a cable thinner than a human finger yet capable of carrying the world's entire supply of electricity. Or it might be used in computers hundreds of times more powerful than those now available but tiny enough to wear on a wrist. Or in impossibly thin, graceful bridges over which the heaviest trucks would roar without making a dent.