Crazy for Quartz
What treasured material preserves Nature's past in fossils, keeps your watch ticking on time, inspires jewelry and more?
What do the following observations have in common?
Deep under the soil of northern Iowa lies recently discovered evidence that a storm of comets smashing into the planet 65 million years ago may have caused the dinosaurs to go extinct.
In Arizona's Painted Desert, 150-million-year-old coniferous tree trunks sprawl for 40 miles, preserved in rock right down to their cellular structure.
All over the world, scientists use computers to record and analyze data.
The answer comes in two parts. First, the common denominator is the mineral quartz, capable of recording geological traumas of the distant past, creating petrified forests and regulating the information in our computers. Second, in each of the above cases, this common substance - so ubiquitous that it forms most of the sand on the world's beaches - is helping us do no less than interpret the history of life on Earth.
Now consider the less scientific side of the human response to quartz: In forms that include color-banded agate, green jasper and purple amethyst, the mineral has beguiled jewelers, mythmakers and healers since ancient civilizations. In our own modern times, collectors pay into the six figures for prime specimens. According to Paul Pohwat, collections manager for minerology of the Smithsonian Institution, some connoisseurs would "cut off both their legs and their left arm" for one of the museum's prize quartz pieces: a hunk of clear crystal encircled by a glittering band of rose crystal. And in the 1980s, a New Age-inspired rage for crystals spawned a multi-million-dollar industry, mostly in translucent quartz.
Why this extraordinary response to a mere rock? According to Richard Berger. owner of a Seattle gallery of fossils and minerals called Museum Associates, the reason is simple: "Crystals are one more powerful expression of nature." And though many minerals create crystals, quartz is the mainstay of the crystal business. In other words, whether in the hands of scientists, mystics or collectors, this inanimate combination of one part silicon and two parts oxygen has long helped human beings to understand and feel close to the natural world.
Berger has arranged his museum-quality collection-including a number of premier quartz pieces-in an indoor rock and fossil garden. He takes satisfaction in watching visitors react, "touched in ways they can't articulate," he says, to an egg-shaped amethyst geode as big as an office desk, cut open to reveal a bed of huge purple crystals. Or to a 2-ton clear rock crystal lit to glow from within. Or to a "quartz silicate concretion," recently discovered in a French mine, with two-million-year-old ripples formed by running water. "In a sense, it's fossilized water," says Berger.
As momentarily speechless as Berger's visitors may find themselves, humankind has generally found plenty to say about quartz. A sampling: Medieval healers prescribed powdered agate to fight the effects of venom. Ancient Romans and members of other long-gone cultures wore amethyst to prevent intoxication. In the twelfth century, women held jasper during childbirth to ward off demons. Early Britons used "star-stones" (quartz pebbles) to treat disease by boiling them in water which the patient then drank.
Such beliefs have now been embraced by many followers of the New Age movement, a catch-all term for a variety of spiritually based philosophies. Not all the New Age lore about minerals involves quartz, of course, but it is a central ingredient. A believer might, for example, hold jasper to increase energy, blue lace agate to achieve tranquility or pink quartz for self esteem.
What do minerologists make of this latest trend? "If the claims about crystals were true," says the Smithsonian's Pohwat, "I'd be very rich, I'd have a lot of girlfriends and I'd have a car that ran on nothing. To me it's a crutch, like giving someone a placebo."
Even Richard Berger calls much of the current fad "abject silliness." Still, he says, the common use of crystals by medicine men and shamans in ancient cultures the world over is hard to dismiss. "There is," he says, "some kind of fundamental pattern played out with cultures that never knew each other."
If there is anything to the healing power of quartz, you may be unwittingly benefiting from it. The watch on your wrist probably keeps time with a sliver of quartz. It may not be much of a specimen compared to the wonders in Berger's gallery, but this writer has it on authority from a Seattle cart vendor of rocks and jewelry that the size of your quartz crystal doesn't matter; your energy likely will be "balanced" as long as you keep the crystal close by. Oh, and your chances improve if you believe that the quartz will help.
There is no question, however, that quartz works to balance, or regulate, your watch. It does the same for radio frequencies, computers, even earthquake-warning systems. All these devices rely on the mineral's piezoelectric property: Given an electric charge, quartz crystals vibrate. Not only that, they resonate at an exact frequency, the rate of which depends on the thickness of the quartz. The phenomenon also works in reverse: When put under pressure, quartz crystals generate an electric charge.
Radio stations started using quartz crystals to modulate broadcast frequencies, otherwise impossible to control reliably, in the mid 1930s. Manufacturers now culture their own optical-quality crystals, using heat to break down quartz, exposing the elements to the beginnings of a "seed" crystal and applying pressure that forces the natural process to run on fast forward.
Whether in nature or in the lab, crystals "grow" when their elements bond with the developing form, aligning so precisely that their structure is always the same. Quartz crystals form six-sided prisms, though pressure and other variables can make some faces- grow faster than others. Impurities impart color; amethyst's purple, for instance, comes from a trace of iron.
Quartz also assumes many other shapes: masses, fine grains and the structures of other objects. Carried by water seeping through organic material, quartz has preserved plants and animals many millions of years old. Other minerals do the same, but quartz is one of the most prevalent-and just about all petrified wood is solid quartz. The specimens in Arizona's Petrified Forest National Park, for instance, consist of fibrous quartz called chalcedony, much of it in the form of color-banded agate.
In Iowa, "shocked" quartz, in the form of grains with fault lines visible under a geologist's microscope, is helping scientists verify that a buried 21-milewide crater, named for the nearby town of Manson, was due to a tremendous impact. The crater may be a relative of the enormous crater in Mexico's Yucatan Peninsula now thought to be the result of a comet striking Earth 65 million years ago. Scientists currently theorize that dust clouds, heat and acid rain fol lowing the Yucatan impact killed the dinosaurs. The crater evidence is bolstered by a thin claystone layer that marks the Cretaceous Tertiary boundary in geological formations all over the planet. A globe sized dust cloud would create just such a layer and shocked quartz is among the ingredients in the claystone.
Where does the Manson crater come in? Scientists have found a second claystone layer just above the first-and astrogeologist Eugene Shoemaker, for one, thinks the comet that struck what is now Iowa may have contributed shocked quartz to that second layer. "I think it's probably the result of not one but many hits," says Shoemaker, who works with the U.S. Geological Survey in Flagstaff, Arizona. "And right now, our betting is that Manson has contributed."
Though thrilling to evolutionary biologists, the notion of the planet braving a blizzard of comets may not be the most comforting thought to those of us who have witnessed shooting stars. Neither is the rather gleeful prediction by astronomers that a hit capable of wiping out humans is as likely tomorrow morning (though we'd know it was on its way) as in a million years. At least if a huge meteor does strike, some future form of intelligence will be able to trace what happened by the shocked quartz the impact leaves behind.
Senior editor Lisa Drew visited the Smithsonian and Richard Berger's gallery to report this story. Photographer Chip Clark is based in Washington, D.C.