Jay Piatek pulls his Jaguar convertible onto the highway frontage road and turns past the billboard that bears his name and a slogan: Weight loss. Health. Motivation. It is here, at the Piatek Institute, on the bland, exurban edge of Indianapolis, that the doctor made his fortune, ministering to thousands of patients who struggle with eating compulsions.

Piatek has his own compulsions. Locked away at the clinic is a climate-controlled vault for his abiding passion: meteorites. With a near-photographic memory, he is able to rattle off the names and provenance of some of his more exotic specimens—Itzawisis, a pallasite found in Namibia; Gujba, a bencubbinite found in Nigeria. “They’re like little movie stars,” he says dreamily.

There is one diva in particular that I’m here to pay homage to: Black Beauty, a shiny, scaly-skinned, 4.4-billion-year-old rock from Mars. It began its journey to Earth more than 5 million years ago, about the time humans and chimpanzees were splitting from a common ancestor. That is when an asteroid struck Mars, catapulting the rock into space. Sometime in the last thousand years or so, orbital mechanics and gravity delivered the wandering rock to Earth. Surviving an incendiary plunge through the atmosphere, it landed in more than a dozen pieces in the western Sahara. There the fragments sat, untouched except by wind and sand. Finally, a nomad plucked a piece from the dunes. After passing through the hands of several Moroccan middlemen, the first piece wound up in Piatek’s hands in 2011. He would acquire nine more.

Black Beauty has since set the collecting world on fire, reaching values of more than $10,000 per gram. (Gold trades for $40 per gram.) The price is in no small part due to the parade of scientific discoveries emerging from the rock’s jumbled-up guts. It is the oldest rock from Mars and chock-full of the planet’s primordial water. Most intriguing of all, it appears to be the first martian meteorite made of sediment, deposited by wind or water. That makes Black Beauty not only a cosmic blessing—sedimentary rocks are fragile and thought unlikely to survive interplanetary launches—but also a boon for astrobiologists. “If you’re going to look for life, you want a sedimentary rock,” says Munir Humayun, a meteoriticist at Florida State University in Tallahassee who led a study that last year pinpointed the rock’s age.

Even if it holds no trace of life, Black Beauty has plenty to captivate scientists. It is a breccia—a rock made of rocks, welded together in a fine-grained matrix. Each embedded pebble has a history to be unraveled. Black Beauty holds not just a geological story but an immense anthology. “We’re looking at the equivalent of a martian geological field area,” says Carl Agee, a meteoriticist at the University of New Mexico, Albuquerque.

Agee led the team that, in a 2013 publication in Science, was the first to recognize that Black Beauty was from Mars—and yet was unlike any of the other 74 known martian meteorites. As expensive as Black Beauty has become, it is still a bargain compared with proposals for a robotic Mars sample return mission. “I sort of half-jokingly say ‘Morocco sample return,’ ” Agee says. “Some of these meteorites, like Black Beauty, are the next best thing.”

About a dozen institutions have paid dearly—or traded choice holdings—for the privilege of working with tiny slices. Many more scientists are in the queue for pieces. And Piatek, through a combination of luck, money, and quick action, has cornered the market. He controls about two-thirds of the 2 kilograms of Black Beauty known to exist. The pieces are waiting for us at the clinic.

PHOTOS: (TOP TO BOTTOM) AHMAD BOURAGAA; MOHAMED AID

In 2012 and 2013, hundreds of meteorite hunters combed the sands of the western Sahara for Black Beauty—and found pieces like this 241-gram specimen.

THE SUN HAS STARTED TO FALL on this steamy July day, but Piatek is just revving up as he parks. Entering the clinic, he shows me a room-sized tank stocked with tropical triggerfish, a tank so big that Piatek puts on a wetsuit and goes diving to clean it. There are empty patient waiting rooms, decked out in a style you might call Greco-Vegas: plastic fruit, purple drapes, faux-Doric columns. A few hours before, they would have been filled with people waiting for 5-minute visits with Piatek and his prescriptions of hormones, vitamins, and stimulants. His fellow doctors may look askance, but Piatek doesn’t really care. “They think we’re just giving out speed,” he says. “I’d rather have my patients love me. Screw my colleagues.”

Normally, Piatek keeps Black Beauty and his other most valuable specimens at a bank vault. But he has just recently returned from the Smithsonian Institution National Museum of Natural History in Washington, D.C., where he attempted to make a trade, and so he hasn’t yet returned the stones to the bank. They lie in a carry-on roller bag inside the clinic’s vault. Piatek punches in numbers and tugs on the door. “Unbelievable,” he says. “Look at that.” The door handle is jammed.

He fetches some tools and pops out the hinges, but the door is still wedged. Piatek calls his niece to summon more muscle: her husband, Brock. “Tell him to bring a couple screwdrivers, and a few pliers, but not little ones.” Then he calls another number. “It’s me, Piatek. I’m coming in with a friend.” He hangs up and faces me. “Do you like steak?” he asks.

RUTH'S CHRIS STEAK HOUSE is Piatek’s customary retreat after watching Indiana Pacers basketball games from his courtside seats. There, over steaks and California cabernet, Piatek begins the saga of a 4.4-billion-year-old rock and the 53-year-old man who owns it.

Piatek was born in Gary, Indiana, to a mother who worked in the steel mills. His adoptive father was a driver for the fire department. He spent college summers at the mill, working in the coke ovens. “It was, like, brutal,” he recalls. “You’re blowing your nose for 2 weeks afterwards and coke is coming out, and it’s not the coke that’s good.” Medical school at Indiana University opened the way to a different life.

After marriage, four children, and nearly a decade as an emergency room doctor, Piatek started his weight loss practice in 1995. Business was brisk. At one point, he was seeing 150 patients a day. But in 2003 his son was working on a fourth-grade school project on meteorites. “What’s a meteorite?” Piatek asked him—and an obsession was born. “I loved that you could get a piece of outer space that’s billions of years old, and you can hold it in your hand,” he says.

There are more than 50,000 named and classified meteorites. The vast majority are chondrites, pieces of asteroids filled with little glassy beads called chondrules. Much rarer—and more expensive—are meteorites from the moon, Mars, and other special bodies in the solar system, such as the asteroid Vesta. At first, Piatek was disappointed to learn that he couldn’t own a piece of everything: Some were locked up in institutional collections, others destroyed or lost. He made a list of priorities and started hunting on eBay, quickly graduating to gem and mineralogy shows. At his peak, he had 1300 specimens. By comparison, Arizona State University, Tempe, which has the largest university-owned collection in the world, has about 2000, says Meenakshi Wadhwa, the director of Arizona State’s Center for Meteorite Studies, who recently traded with Piatek for a 20-gram cut of Black Beauty.

A few years ago, spurred by chest pains and intimations of his mortality, Piatek decided to cut back on both his working hours and his meteorite addiction. He brought on another doctor to do most of the work at the clinic. And he sold 400 of his specimens—including a couple of Black Beauty fragments—for more than a million dollars to Naveen Jain, a tech billionaire. Although the transaction delighted his wife, who never quite understood the value of collecting these rocks, Piatek winces at the memory. “I had stuff that no one had,” he says. “I had the one that hit the lady, I had the one that hit the dog.”

Piatek has whittled his collection down to a prized 400 or so. But his passion still burns. One paramount goal: completing his collection of pallasites, pretty meteorites that often contain green olivine crystals suspended in a gray matrix like luminous polka dots. Of the 59 pallasites that are possible to get (a few others reside in untouchable collections), Piatek has 57.

One, the El Rancho Grande pallasite, came in a trade from Agee, a genteel scholar who was once chief scientist for NASA’s Johnson Space Center in Houston, Texas, and now curates the University of New Mexico’s meteorite collection. “Our relationship was sealed at that point,” Piatek says. He has donated more of Black Beauty to the University of New Mexico than anywhere else, elevating its collection from obscurity.

The relationship would prove crucial when it came to figuring out the rock’s origin. In 2011, Piatek bought the first piece, a 320-gram mass, from Aziz Habibi, a dealer from Erfoud, Morocco, who had been regularly sending Piatek pictures of meteorites for sale—including one he called Black Beauty. Almost on a whim, Piatek paid $6000 for the stone—cheap in the meteorite world—thinking it was nothing more than a regular chondrite. (Piatek says he later paid a bonus to Habibi when its true nature was revealed.)

Piatek sent the stone to Agee, who wasn’t convinced that it was a meteorite at all. It didn’t have the heft of a chondrite, which are typically rich in dense metals. And the scaly skin—the “fusion crust” that forms on the superheated surface of a falling meteorite—seemed so shiny that it might be fake. “I thought someone had taken a desert stone and spray-painted it,” Agee says. Nonplussed, he stuck the rock on a shelf for a few months. Eventually, in the fall of 2011, he took a diamond-tipped rock saw, sliced off one end of the stone—and marveled at what he saw inside. Dark, angular crystals of pyroxene floated alongside white, chunky feldspars. Large, faint pebbles sat next to tiny, dark beads. It was evocative of the lunar breccias Agee recalled from the Apollo days—except that Black Beauty’s spherules were much more diverse.

Agee now knew he had a meteorite, but what was it? He chipped off a gram piece and put it under an electron microprobe, which uses an electron beam to excite atoms in the rock’s minerals. The atoms then emit x-rays that reveal the sample’s chemical makeup. It turned out that the rock had an elevated manganese-to-iron ratio—higher than that in Earth rocks and consistent with other martian meteorites. Next, Agee and his colleagues used a laser to extract water molecules trapped within minerals in the meteorite and fed them into a mass spectrometer to calculate the ratio of deuterium, a heavy isotope of hydrogen, to ordinary hydrogen. Every place in solar system has a distinctive ratio. Lo and behold, the copious water in Black Beauty was Mars-like.

Agee was convinced that Black Beauty was from Mars—and also that it was unlike all the other martian meteorites. In a talk at the Lunar and Planetary Science Conference in Texas in March 2012, he and his team described the rock as a volcanic breccia—a mélange of mineral crystals that formed underground in different slow-cooling magma chambers and were blasted together and fused by an explosive eruption.

After Agee’s team published their findings in Science in February 2013, Piatek’s life instantly became more complicated. “You guys killed me,” he says. Almost overnight, Moroccan dealers raised their asking prices for chunks of Black Beauty from tens to hundreds to thousands of dollars per gram. And while Piatek had previously had the market to himself, he now had rivals. Chief among them was another doctor-cum-collector: a Frenchman named Luc Labenne. “I knew he was going to be my competition,” Piatek says. “Then, it was on.”

LABENNE HAS A SMALL PIECE OF MARS in the pocket of his bright red pants. He came to Casablanca, Morocco, this past September for the annual meeting of the Meteoritical Society. Like many collectors and dealers, Labenne cares deeply about the science and spends much of his time at the conference diligently attending the scientific sessions—especially the dozen talks that focus on Black Beauty. But he is also here to do business. He has just paid a local dealer nearly €10,000 for a 25-gram martian meteorite called a shergottite. The most common type of martian meteorite, shergottites are relatively cheap and not nearly as scientifically interesting as Black Beauty, but this particular rock’s delicate fusion crust should boost its value. “It’s just magnificent,” he says. “It’s black and fresh. So great.”

Like Piatek, Labenne is a semiretired physician. But unlike the frenetic Piatek, Labenne is contemplative and keeps his own counsel. He often takes several trips a year to Libya, Morocco, Chile, and Oman to hunt for meteorites with his brother. Driving slowly and systematically across the desert from sunup until sundown, he takes a quiet pleasure in scanning the landscape for dark objects that don’t belong. At night, he uses LED lights to search for meteorites near the campsite—and has found two lunar meteorites this way. Labenne owns seven pieces of Black Beauty, the second most after Piatek, and has been a primary source of material for scientists in Europe.

During a coffee break at the conference, Labenne lurks quietly behind Habibi, the flashy, chain-smoking impresario of Morocco’s meteorite dealers. Habibi has a suitcase open and is showing off samples to scientists, unwrapping them from foil or old socks. He was hooked on fossils and meteorites as a teenager, when he explored the quarries in his hometown, Erfoud, for ammonites, the nautilus-shaped mollusks that lived hundreds of millions of years ago. Habibi now operates a 140-room hotel in Erfoud, but his main love is meteorites—and the wheeling and dealing in them.

In 2011, Habibi was in the town of Agadir, recovering from gallstone surgery, when he met another dealer who offered him a shiny black stone. No one could agree what it was, or was worth, and Habibi passed on it. But as he was driving away, he had second thoughts. He turned around and made a deal for the first, 320-gram piece of Black Beauty.

With meteorites, where there is one, there are usually more. In 2012, as reports of Black Beauty’s significance began circulating, Habibi went searching. He worked upstream from the Agadir dealer and discovered that the original finder was a nomad who worked the desolate terrain between Mauritania and southwestern Morocco. The nomad, whose name is Bahba, had picked up the stone from a void, featureless place called Rabt Sbayta (“sand dunes of Sbayta”), a few hundred kilometers from the coast within the disputed territories of Western Sahara.

Habibi wasn’t the only dealer making inquiries. Rabt Sbayta soon became a village, with dozens of encampments and hundreds of people combing the shifting dunes. The rules were simple: finders keepers. A “strewn field” emerged: a stretch of desert roughly 10 kilometers long and a few kilometers wide strewn with pieces that fell as Black Beauty broke up in the final moments of its descent. Newfound stones were sold up through the food chain of dealers like Habibi and usually wound up in the hands of Piatek or Labenne. “It was a big race,” Habibi says. “It was the most expensive stone of my life. We were paying $1000 per gram here in Morocco. I have never been so stressed.”

INSET: GOOGLE MAPS/(DATA) AHMAD BOURAGAA

Meteorite collectors, dealers, and scientists are intertwined in wary but symbiotic relationships. Science gains from a long-standing “20/20” rule: To get a meteorite name and an official classification—which makes a stone more valuable—a dealer or collector must hand over to a scientific institution 20 grams or 20% of the weight of the stone, whichever is less. Scientists have now studied and classified seven of the fallen Black Beauty stones. But the rest—including most of Piatek and Labenne’s stones—are unclassified, as the owners have little incentive to give up the material gratis.

Hasnaa Chennaoui, a meteoriticist at Hassan II University in Casablanca who organized the conference, complains that the 20/20 rule rewards scientists in Europe and North America, where collectors have the most money and scientists the best equipment. Her university lacks an electron microprobe—the primary tool used for classification—and so she understands why collectors and dealers tend to go to Western scientists. But she feels that she and her Moroccan colleagues ought to have a chance to study their own country’s meteorites. So far, she has had no research access to Black Beauty. “Yes, it goes to science,” she says, “but to science outside of Morocco.”

ALL THE PLAYERS in the world of meteorites have their incentives. Hunters want to make money. Collectors want to make a complete set. And scientists want to make their name. That holds for Florida State’s Humayun, who knew that Black Beauty was going to be special from the moment Agee spoke at the 2012 Lunar and Planetary Science Conference. In his talk, Agee presented the results of the isotope analysis for oxygen as well as hydrogen. The hydrogen for isotopes were consistent with Mars-like water. But the oxygen isotope ratios were puzzlingly different from those in all other martian meteorites. Humayun thought he had the solution. After the talk, he jumped up and asked for a sample. “Carl said he’d give me one, but he wasn’t in a hurry,” he says. “I just wanted to get my hands on it, to tell the truth.”

Tidy in dress and excitable in manner, Humayun is a perfect foil to the laid-back Agee, who says he wasn’t trying to sideline Humayun from access to Black Beauty; he just didn’t get around to sending him any in time. So Humayun arranged to work on a sample held by the National Museum of Natural History in Paris. He realized that the skewed oxygen isotope ratios could be explained if the rock had been exposed to martian air or water for a long period. That couldn’t have happened in Agee’s explosive-eruption origin scenario, because the rock’s interior would have been quickly sealed off from the elements.

“It struck me,” Humayun says, “that this was not a volcanic breccia.” Instead, Humayun argues, Black Beauty is a sedimentary rock. The mineral and rock ingredients had formed igneously, from cooling magma, but they then eroded into sediments that were altered by water and air. Sometime later, asteroid impacts fused the breccia into a solid rock, before a final impact launched it into space. Humayun published his conclusions in Nature in November 2013.

PHOTO: CARL AGEE/UNIVERSITY OF NEW MEXICO

The Nature paper also reassessed Black Beauty’s age. Agee’s team had pegged it at 2.1 billion years, based on a radiometric dating of rubidium and strontium, averaged across the sample in bulk. That age would have made Black Beauty much older than the shergottites, which are on average a few hundred million years old, but not nearly as old as the 4.1-billion-year-old Allan Hills 84001, a softball-sized Mars meteorite that sparked lasting controversy in 1996, when some scientists claimed it contained fossilized bacteria. In Humayun’s scenario, however, different components of the rock could have formed at different times.

Humayun’s team analyzed rock pieces rich in pyroxene and feldspar—minerals that would have been among the first to settle out of a cooling magma chamber. In these regions they found zircons, hardy little crystals that are valued because they suck up enough radioactive uranium to be used for dating. The age Humayun’s team obtained from these minerals—4.4 billion years—would make Black Beauty, or at least these regions within it, the very oldest martian meteorite. It would also mean that, just a hundred million years after Mars itself coalesced as a molten ball of rock, its crust had cooled enough to support magma chambers in which zircons could form.

Now scientists are pressing further into the rock. Every cut and slice seems to yield a surprise. In September, at the Meteoritical Society meeting in Casablanca, Humayun reported finding veins of pyrite, fool’s gold. The veins crosscut other parts of the meteorite—meaning they must have been among the last features to form while the rock was sitting on Mars—and the mineral is intrinsically interesting because it forms in the presence of water.

Also at the meeting, Francis McCubbins, a colleague of Agee’s at the University of New Mexico, presented evidence that the rounded appearance of the large faint pebbles suggests erosion by water or wind. CT scans have also revealed smaller iron-rich spherules resembling “blueberries,” the iron-oxide concretions discovered on Mars a decade ago by the Opportunity rover and thought to have precipitated out of water. The edges of these veins and spherules would all be good places to look for organic signals, says Andrew Steele, a biogeochemist at the Carnegie Institution for Science in Washington, D.C., who is probing the rock for organics.

So far, Steele has found no hint of martian biology—just trace amounts of organic molecules associated with volcanic processes. But he has found plenty of Earth bugs in the cracks—something that he takes as a good sign. “It’s a very habitable rock,” he says. “All it needs is a little warmth.”

While the scientists continue to poke and prod, Piatek totes his martian meteorites to events and institutions around the world. He is a loving but not always careful guardian. In 2013, after the Tucson, Arizona, Gem and Mineral Show—a mecca for meteorite collectors—Piatek visited the house of Robert Ward, a meteorite hunter, dealer, and collector in Prescott, Arizona. The two started drinking and playing around with Ward’s new night vision goggles. They figured that Black Beauty’s fragments, full of heat-retaining minerals, would stand out in the darkness like living things. So Piatek hid the stones outside in a freshly fallen snow. “We got done with the tequila and then remembered the Black Beauties hanging out in the snow,” Ward recalls. “It was like an Easter egg hunt,” Piatek says, chuckling. “It was crazy!”

TOWARD THE END OF DINNER at the Indianapolis steakhouse, Piatek receives a text from his niece-slash-personal assistant. “We’re in!” he says. He asks the waitress to bag up our scraps of beef for the 13 dogs he and his wife keep at home.

Brock’s sanctioned break-in has done the job. Piatek unzips the roller carry-on bag and begins to take out his pieces of Black Beauty, one by one. Accidently, he drops one and picks it up a bit sheepishly. “Oh, yeah, Smithsonian would have died on that one,” he says.

Piatek is handling the oldest rocks on Earth—hundreds of millions of years older than any rock native to our planet, where the constant churn of plate tectonics renews the crust. Black Beauty waited billions of years to get to Earth. Then, all in the last few years, pieces of it traveled to Rome; Washington, D.C.; Tucson; Tempe; Albuquerque; Toronto—a meteoritical Grand Tour. As Piatek continues to make donations and trades, and as researchers slice and dice the stones into ever smaller chips, Black Beauty is spreading itself, entropically, across the world. Mars to Earth, rock to dust.

Piatek shows me his favorite Black Beauty party trick. He takes the 525-gram main mass and the 241-gram piece and a little 7.7-gram shard, and twists the three around until, like a jigsaw puzzle, they lock perfectly into place—the way they must have been before the parent body broke up in the atmosphere. “Look at that,” he says, marveling at the fit. “Isn’t that crazy?” In this moment, the arrow of time spins backward, and you can imagine all the pieces coalescing in reverse motion, gathering heft and speed and youth as they return from whence they came. Earth to Mars, dust to rock.

A few months later, I call Piatek and catch him creaky-voiced, lying in the bed of a hotel room in Bally’s casino in Las Vegas, Nevada. Things have not gone well lately, and not just at the craps table. He and his wife are divorcing. His kids have left the nest. He’s not going to renew his Indiana Pacers season tickets. He is resolving to lead a simpler life, spending more time with family and friends. It also means shedding more of his meteorite collection. But not Black Beauty. That’s his touchstone, his bedrock—monetarily and metaphysically. It has both the pedigree of 4.4 billion years and the promise of a future.

“Some Black Beauty I’m going to have to keep forever,” he says. “For the kids, or for when I die. Because they might find something in it.”

“What if they find life? It’s the ‘what if’ is what I’m into. It’s like wow. That’s the cool thing about it: the potential of Black Beauty.”

*Correction, 26 November, 12 p.m.: The photograph for the "Rock of ages" chart should have been attributed to Carl Agee of the University of New Mexico.