ANYBODY WANT A 300 Ton JADE BOULDER ?
What follows is the back story to the account of some of my work seen in The New York Times - Olmec Jade Discovery , The New York Times .May 22, 2002
The search for the lost jade mines of the Olmec civilization has fascinated archaeologists since the ice blue and sea green stone was first shown to the Conquistadors by the Aztecs.who knew not whence the ancient jade axes ,masks and amulets they treasured as heirlooms came, because they were obtained largely by robbing Maya tombs, just as the Maya had ripped them from Olmec graves and ruins. This layered confusion of sources has vexed archaeology since Alexander von Humboldt set out for
Central America in 1799.
Only in the last few decades has the riddle of the jade's sources been partially solved. The New York Times kindly reported the progress I made as Field Director of Harvard's Mesoamerican Jade Project in the article linked above, and new work by my colleagues is in press. My version of the back story follows- the pictures and maps, I'm afraid, will have to await its publication- or a grant in aid of more field work.( I take PayPal and can provide a 501k]
The Hunt for Olmec Blue
Copyright 2006 Russell Seitz
As Hurricane Mitch tore inland from the Caribbean in 1998, two feet of rain lashed the Maya temples of Copan and turned the mountain
ravines of Eastern Guatemala into white water. A Maya corn farmer stranded at the base of one faced a stark choice: scale the thundering cascade before him or drown in the rising Rio Jalapa at his back He started climbing. Halfway up the mile high escarpment, the walls of the steep watercourse started to crumble; a clatter of violet-blue screen forced him over a razorback to where a rooster tail of white water roared out of a split boulder the size of a bus. Inching along it, he found himself facing a patch of blue green translucence.
He had no time to wonder what the wonderful rock was called, and continued upward arriving at the top, half drowned and shivering; he found his house a roofless wreck and his fields blasted flat. La Crucita had lost its corn crop, and nothing more could be planted until the rains came again. Late in the hungry winter that followed the destitute campesino hear that a few days walk down the Rio Jalapa, a Chinese entrepreneur was seeking translucent stones for carvers in
Recalling what he had seen in the storm enlarged ravine, the campesino climbed down Monkey Gulch, and back up Quebrada Seca, gathering samples to offer Mr. Wang at his impromptu mining camp ten miles downhill and downstream. The entrepreneur’s mining permit was for serpentine but he knew jade when he saw it, even if the color was strange. He had no idea that the worst storm in a millennium had exposed a treasure lost for a hundred generations the blue jade of the Olmecs. Mr. Wang always carried a pistol as is wise in the mountains of
Jalapa, but decided he would need a more in the way of lawyers, guns and money to exploit the find.
Jade is one reason why the Stone Age is still with us. Not all of our contemporaries are living in the same time. Jade war clubs struck down Victorian Britons attempting to colonize New Zealand , and even today, tribal groups in Papua continued to make and treasure axes made from stones as strong as steel .
This Stone Age strategic material was important in peace as war. For eons, fire was man’s only practical tool for clearing forests, because while slaked flint axes start razor sharp, they dull fast and shatter alarmingly. Logging as we know it began with the advent of strong ground stone tools a scant ten thousand years ago. Felling a single tree may break a dozen brittle flint axes, but one jade blade can fell a grove. Modern geologists continue to be amazed by jadeite boulders tough as blacksmiths anvils that blunt sledge hammers, and defy dynamite.
Yet while jade resists impact, it can be patiently ground away- it is slightly softer. Than quartz, so sandstone can sharpen it as readily as steel. The same is true of nephrite, another unnaturally tough silicate mineral though the two differ in chemistry, they are hard to tell apart, and both were prized. But while nephrite comes in muted shades, jadeite can span the rainbow,
Just as fibrous crystallites of aluminum silicates make the difference between fragile silicate glass and tough porcelain and stovetop ceramics, the microstructure of jade renders it far stronger than single crystals of the minerals that comprise it. ‘ Nephrite’ , and ‘Jadeite ‘ denote single mineral rocks resulting from metamorphism at considerable pressures - up to 10 kilo bars , but relatively low temperatures . Jadeite has a highly compressed crystal structure, and is unstable at the earth’s surface, much as diamond is. But like diamond, it transforms s into a softer, more stable low density form on heating, and expands some 15% as melts into glass.
Both minerals are commonly impure, and alloy with structurally related silicates. The rarely encountered pure minerals ( chemical formulas with subscripts here ) are colorless or white, but colorful impurity ions lend them many hues - iron renders nephrite spinach green, and chromium creates the emerald green ‘Imperial jadeite’ prized by the Chinese and Maya alike. The unique ‘Olmec Blue’ hue comes from the interaction of titanium and iron ions. In almost all deposits, a mixture impurities dulls the color of all but a tiny fraction of the stone- the 300 ton boulder exposed by the hurricane has quarter -sized dots of gem green and square foot windows of aquamarine scattered through a dull sea of pastel blue-green and grey.
A skilled lapidary with diamond power tools can cut any gem in hours or days, but experimenters using sandstone and elbow grease find jade celts and axes take a month to grind by hand. The life size jade masks and hefty axes the Olmec fashioned may have taken a year or so carve. Once made, massive jades seldom break when dropped - or struck - their ability to shatter flint and obsidian made jade armed warriors formidable, but while plaques of jade may stop arrows, jade weapons proved useless against the arms and armor of the Conquistadors. Montezuma tried to buy them off with jade, but while Cortez coveted porcelain and silk, he had never laid eyes on Chinese jade , and did not suspect Aztec gems might be worth ’a fortune on the far side of the Pacific. So Cortez spurned an emperor’s ransom in green and blue Maya and Olmec heirlooms like so many glass beads, and returned to enforcing his demands for gold with Spanish steel.
Jade once flowed freely into the
Valley of Mexico, but as the Olmec civilization faded so did the jade trade /. Why remains a mystery, for sources like Quebrada Seca still hold thousands of tons .When the Olmec of Mexico’s tropical Gulf Coast first began importing jade from Guatemala around 1600 BC, it arrived mainly as large celts shaped near their source. After its transformation by sophisticated Olmec artisans, local traders and perhaps distant trade partners brought it north to the Vally of Mexico and south to Guatemala’s Pacific shore. Arriving in Vera Cruz the Spanish encountered half buried giant stone heads whose features unmistakably resembled those of the equally ancient jade masks. Only in the 1930’s did archaeologists uncover the staggering caches of jade carvings that revealed blue jade as that vanished culture’s hallmark.
As Olmec culture waned and the first Maya temples rose jade mining seems to have declined. Archaeologists find fewer and smaller jade objects as dates progress from 600 BC to 600 AD , and by around the time of Christ , Olmec era graves were being looted, and the jades in them recycled , shrinking each time they were recur . Pendants that are mere slivers of Olmec jade death masks carved a thousand years earlier and a thousand miles away have emerged from Costa Rican sites dated to 400 AD.
By Aztec times, some jade mines were as lost as King Solomon’s. And the true name of those who first carved blue jade had vanished as well It is ironic that the first writing in the
New World ,developed nearly 3,000 years ago has yet to reveal what its authors called themselves. ”Olmeca” is just what the Aztec’s called Southeasterners--the ‘Rubber People”, who made the balls used in the sacred game of Moctezuma’s court.
The few Precolumbian jade objects returned to renaissance Europe by the Conquistadors ignited a late-renaissance antiquarian controversy , for they resembled ancient jade axes unearthed around monuments like Stonehenge Fantastic archaeological theories are nothing new, since Europe had no known source of jade, some speculated the Neolithic artifacts belonged to American Indians crossing the Atlantic in the days of Julius Caesar !
This outlandish controversy had only one clear solution- find the source. In 1799 Alexander von Humboldt put this ambitious task on his list of things to do as he embarked for
Spain's American colonies on a voyage of scientific exploration. The young naturalist little imagined he would ignite one of the longest treasure hunts in modern history-- archaeologists are still finishing what he started three centuries later. Humboldt never found a jade outcrop, but he established the foundation of Precolumbian archaeology by applying the basic principles of stratigraphy to the historical succession of the Zapotecs, Maya, Toltecs and Aztecs. The Olmecs place as the region’s oldest culture made their jade carvings the most sought after and valuable of all Precolumbian art objects, and their mysterious source became an obsession to archaeologists, collectors, and grave robbers alike.
Though Humboldt’s geological exploration never found the jade’s source ,his scientific work so benefited Mexico’s silver mine owners that they showered him with Olmec and Maya celts and carvings before he headed home in 1804. Pausing at Philadelphia, he was summoned to Monticello to provide Thomas Jefferson with geological hints for the Lewis and Clark . The Prussian polymath’s travels also inspired Darwin and Wallace, yet Humboldt went to his grave still puzzled by the blue stone's origin.
The hunt resumed in 1888.Having observed that many ‘Aztec’ jades were carved out of older celts, Tiffany chief gemologist George Kunz contacted Zelia Nuttall of Harvard' , who deciphered the 1598 Chronicle of Tezozomoc. It related that the Aztecs collected taxes from a far southern region termed 'Jadeland,' That was enough to send Kunz south to Oaxaca, where he found no mines, but a local lawyer sold him a hefty jade treasure that now graces the American Museum of Natural history The Kunz Axe is the beau ideal of a bloodthirsty heathen idol- a fanged and snarling blue jade were-jaguar with a bolt of emerald green quetzalitzli jade across its back. The first piece of jade seen in modern times was brought to light in 1954, not by an archaeologist’s trowel, but the whirling tines of a tomato cultivator in the sreamy Motaguavalley in Guatemala
Geologists are not prospectors, and the Smithsonian’s scientists were more interested in thoroughly understanding what they found in the valley than scouring them there hills for more. Their reluctance was compounded by guerilla war in the’ hills’ in question- the 10,000 foot high Sierra De Las Minas .The first jade found was no treasure -though tough enough to wreck plows, it was the color of moldy oatmeal. A Smithsonian expedition soon confirmed that the dull and opaque stone was indeed jadeite, but not the jade Olmecs carved or the Aztecs coveted. It was from one of many ugly outcrops ignored by the ancient jade gatherers who picked the river clean of precious blue and green cobbles, much as the 49’ers stripped
Though unexportably bad, the jade remaining in the valley gave rise to a local tourist industry. Bad jade bought for pennies a pound in the remote countryside could be carved and unloaded for hefty sums to tourists visiting the colorful highlands or the Maya temples of
Tikal.Dealers romanced these unpromising stones by sand blasting them with Maya glyphs and announcing they came from “The Quarry Of the Kings “ Few package tourists escaped a visit to a ‘ jade factory’ and many departed with hefty souvenirs made of jade rejected by the civilizations it supposedly represented .
For decades, Archaeologists and visiting geologists were hoodwinked too. As were many dealers , who bought jade said to be from the valley from secretive local prospectors who in fact procured it high in the surrounding mountains The small amounts of translucent jade they found almost never entered the tourist trade. A single cobble of vivid light green jade procured by Guatemala’s largest tourist dealer in 1987 was still being parceled out as gemstones in 2001, and a single blue pebble was all French archaeologists could find searching south of the Motagua in 1996.
This tantalizing failure of the mother lodes to materialize arose because Guatemalan official history emphasizes the Maya at the Olmec’s expense- few in the countryside had any conception of who had been looking for what 3000 years before. Those that did had a vested interest in the sources staying lost .In the late 1960’s collectors paid millions for ‘Olmec Blue’ jade masks, celts, and statues looted from southern
Mexico’s Rio Pesquero region. The art market wanted more of these archaeological treasures, and as long as the mines remained lost, the stone itself served as a guarantee of antiquity. Absent supplies of raw ‘Olmec blue’ clever forgers tried other stones worked by Olmec lapidaries especially translucent Bowenite serpentine, but ‘Olmec blue’ remained in a class by itself, and connoisseurs prided themselves in believing they could recognize it on sight.
The word ‘Maya summons visions of elaborate temples strangled by jungle growth, They inhabited a more diverse landscape, wisely preferring more open terrain, but despite the inroads of ranching and agribusiness there is still a lot of vegetation, much with thorns and an attitude in the way of field researchers in the jadeite deposits in the lower elevations in sight of the Trans-Atlantic highway on the valley floor, but few tackled the thorny heights. Scientists are human, and when temperatures exceed a hundred degrees, resolve to see more ‘ground truth’ drains away as rapidly as canteens empty.
Especially when the unmapped rocks start several thousand vertical feet up a mountain likelier to have guerillas on its far side than cool water on its summit, The more you sweat, the more receptive you became to the common wisdom--that no jade could outcrop in the ostensibly alien geology south of the river, and that it did not pay to go bushwhacking uphill past the elevation of the last purple splotches on the map indicating potentially jade–bearing serpentine. The result was the drawing of maps that though they seem ludicrous today, left a generation of archaeologists impressed with “The Motagua Valley” as their only textbook jade source.
Jadeite and nephrite are basically one mineral rocks made of a sodium rich pyroxene or an amphibole or respectively. But not all pyroxenite or amphibolite rocks are jade, any more than all limestone is marble. Metamorphic rocks differ in texture, strength, and appearance depending on how they're cooked. Those taken tens of kilometers deep into the Earth's crust or upper mantle by subduction are usually heated as fast as they are pressurized. Not always- a rare exception can transform pyroxene minerals into jadeite rocks rivaling the toughness of modern engineering ceramics.
A wet slab of basalt seafloor shoved under a continental margin may stay relatively cool-300 C, instead of becoming red hot like the mantle rocks beneath- if it does, it can transform into the garnet-bearing rock called eclogite. But if it stays relatively cool despite the intense pressure 20 miles down, it may resurface millions of years later bearing minerals unstable at the Earth's surface. Diamond is one. Jadeite is another.
But just as hot diamonds can revert to graphite on the way up, jadeite too can decompose as it ascends. Jadeite is stable deep down where sub ducted seawater salts react with minerals to form it, but release the pressure and its dense crystal structure can spring open. Melt jadeite, and it expands alarmingly into molten glass, but squeeze that hot glass hard enough in a high-pressure press and crystalline jadeite reforms.
As with Baked Alaska, it’s surprising that jadeite exists at all. Only in a dozen places worldwide has geology provided the wild ride needed to bring it up intact. Geologists seeking high-pressure –low temperature rocks generally find only green schist arising from their destruction by retrograde metamorphism. The translucent surface of jadeite is chemically fragile. The loss of ions into ground water over centuries can corrode ancient jades into mere skeletons of their former selves. Only very rarely do chemistry and physics and natural history conspire to produce jadeite of stunning emerald translucence. Cortez may have sneered at the handful of green baubles Montezuma offered, but in 1998 a strand of imperial green jade beads sold for nine million dollars inHong Kong
The great Olmec tradition of solid jade funeral masks lasted into Maya times, but the supply of large newly mined material to carve them from did not. The magnificent 8th century tomb of King Pacal of
Palenque attests to almost unlimited wealth, yet though his sarcophagus lid weighs nearly ten tons, his death mask is a motley patchwork of jades weighing less than an ounce. Something happened to the supply of jade, not the demand for it. But mines are hard things to lose. And find – when decades of research in Guatemala failed to turn up anything remotely Olmec looking, the hunt turned elsewhere.
In 1979, rumors ran that a new wave of forged Olmec carvings stemmed from a source an inauspiciously located on a stretch of
Costa Rica's Pacific coast troubled by the spillover of Nicaragua's civil war. Teams from two museums raced to the site. Their arrival on the same day by land and by sea left Contras and Sandinistas agreing that archaeology and gun running had a lot in common . The rumored jade proved to be nothing more than metamorphosed limestone,
The search for Olmec Blue extended from a banana port famed among mariners as “The armpit of the
Caribbeanto high alpine forest with frigid streams spanned by the regions unique gift to vernacular architecture- the barbed wire suspension bridge. Twenty years after the Peabody Museum jade researcher’s ran afoul of Guatemala's civil war; they still found abandoned fincas with death squad blood graffiti on the walls and jaguars in residence. But increasingly remote towns now boasted internet cafes, though some served the “Colombian Business” or a thriving trade in looted antiquities.
Antigua Guatemala in1999, I saw varieties of jade unseen in raw from for centuries unloaded from chicken buses by campesinos in hopes of finding a market. Many were completely unlike anything seen by geologists in the course of decades of field work the Motagua Valley.Ironically, few of the Maya who brought them had ever heard of the Olmecs, but even fewer of the Antiguadealers had ever visited their rural suppliers. let alone ventured into the mountain wilderness days away from any road .
I persuaded one of the most enterprising
Antiguajade merchants, Carlos Morales, to aid my search. It took months for Morales locate Carlos Gonzales of Teculutan , and months more for Gonzales persuade one of the actual discoverers , a diminutive Chorti Maya known only as Antonio, to take us to deposits farther into the Sierra de las Minas than the dealers had ventured. Getting to the first of the 'Olmec' veins he had uncovered entailed a two-day 6,000 vertical foot climb over the Front Range
and around the rim of the kilometer deep Rio Blanco canyon into the heart of the mountains
There, at over a mile elevation, ancient potsherds still lay alongside the wide vein of jade Antonio had discovered. The first samples brought back and analyzed persuaded the 'Jade Raiders ,' from the American Museum of Natural History to come on down and see what I had seen ,I also recruited archaeologist Karl Taube of UC Riverside, whose diligent bushwhacking revealed an ancient dry stone road leading for miles along the mountainside to the ancient mines. Fluent in Maya and Spanish, he soon coaxed others to reveal Quebrada Seca; nearly thirty miles south, where in 2001 we encountered the 300 ton mass of emerald flecked blue jade that Hurricane Mitch uncovered. It sits ignored and overgrown, in a serpentine barren too poor to farm, though green grass sprouts atop the alkali rich jade itself.
So much for “The Motagua Valley” as the erstwhile source - by 2005 , the hunt would find veins on the adjacent geological fault lines, from close to Copan, to 100 kilometers north of the ancient center of Kaminal Juyu, expanding the area of the Olmec sources to a thousand square miles .These finds mean redrawing geological maps of how the Central America isthmus is divided The Olmec Blue jade from the southern deposits is roughly 125 million years old , while those from the North American Plate side of the fault along the valley formed only some 75 million years ago suggesting deposits brought together by continental drift.
Such difference may one day help resolve which artifacts began as Olmec carvings, and which as raw jade from later Maya mines. Some things remain a mystery. When so much jade remains – literally millions of tons over almost a thousand square miles how could it sink into such obscurity for so long? What did the Olmec trade for it-and the ancient Costa Ricans? The answers may be a long time coming.
Some look to the landscape for an explanation. The Sierra are young mountains raised out of old rocks, but Jalopy’s jade fields are pocked with volcanic bombs and maar craters and overshadowed by the cone of extinct Volcan Jumay In 1902 ,distant Volcan Santa Maria blanketed half of Guatemala in ash--extinct is not a word wisely applied to volcanoes near a rumbling suture of two tectonic plates. But this does not mean the Olmec jade trade ended Hollywood style, with miners turned to toast in a prequel to
Pompei. Californians fear wet season landslides more that earthquakes or volcanoes and Quebrada Seca cuts an unstable five thousand foot slope whose upper reaches are encased in prehistoric ash beds whose slippage could obliterate it yet again.
Looking at the hardscrabble cornfields and thorny chaparral of today , it is hard to imagine that Jalapa was once mantled in a rain forest that once masked the geology below just as it swallowed the ruins of nearby Copan – the process that gives rise to lost cities can obscure mines as well .There are more questions only field work and controlled excavations can resolve , but we know this much for certain: in a matter of hours, hurricane Mitch tore more jade loose from these mountainsides than millennia of stone age mining. It will be a long time before Quebrada Seca sees another perfect storm.