THE NEW ALCHEMISTS

The ancient alchemists sought for gold, but the new alchemists have found diamonds—in nearly unlimited quantities, and just a good squeeze away—reports Hazen (Science/George Mason University; coauthor, Science Matters, 1992, etc.) in this sparkling gem of technological history. The trick is getting that squeeze exactly right. Diamonds form naturally one hundred miles below the earth's surface, where the pressure is one hundred pounds per square inch. How many are there? ``Billions of tons of diamonds,'' says Hazen, who loves to drop stunning statistics. When the rare handful reaches sea level—only through volcanic activity, it seems—everyone wants them, for their beauty, their hardness (more atoms per cubic inch than any other substance), their refraction (light passing through a diamond is slowed to 80,000 miles per second). But can we make them in the lab? Early attempts resulted in catastrophic explosions. Then came Percy Bridgman, a Harvard wizard who broke the high-pressure barrier by inventing a press that could squash ``just about everything he could get his hands on''—an invention that won him a Nobel in 1946. In the early 1950's, a weird Swedish firm, basing their research on clues in Norse mythology, managed to synthesize a few diamonds—but the real triumph came with the work of Tracy Hall at General Electric in the mid-50's. By 1960, everyone was making diamonds from all sorts of substances, even peanut butter. Today, the quest for higher pressures continues, using synthesized-diamond anvils (one millibar has been reached, ``the pressure you'd feel underneath a stone monument roughly 2000 miles tall'') and leading to new models of the earth's interior and the possible discovery of new exotic substances, such as metallic hydrogen. Multifaceted, and glittering with drama and wit. (B&w photographs, line drawings)