Posts Tagged ‘Precious Minerals’

Gold Dust

Saturday, December 10th, 2011

The classic view of Superstition Mountain, from the Lost Dutchman State Park, Arizona.

  Let’s talk about gold. Not just any gold, but lost gold. If there’s one thing more appealing than found gold, it’s lost gold. Because that means that the gold – maybe an unknown, vast quantity of it – is still out there somewhere, just waiting to be found. Like fairy-dust sprinkled from a magic wand to vitalize some situation, a dusting of the lure of gold can make a place attract people – those people looking to make it big.

  Sometimes they win; sometimes they lose.

  And sometimes they die.

  We have our own place of temptation right here in our backyard: the Superstition Mountains. For the past century or more, this rugged range of desolate, inhospitable, and yet beautiful rock formations just to the east of Phoenix has drawn countless treasure seekers. The goal? A mysterious cache of gold, or gold ore, or maybe even a mine itself. Who knows which? That’s part of the mystery, and the draw of the place.

  In 1891, one Jacob Waltz, a German immigrant and prospector, known locally as the “Dutchman” (men from both the Netherlands and Germany were then frequently called that in America), died in the Phoenix home of a friend, Julia Thomas. On his deathbed, Waltz described to her the location of a gold deposit of which he knew, deep in the Superstition Mountains. But in his possession then were only a few gold nuggets, and he never had appeared to be a wealthy man.

  Yet, Ms. Thomas and two of her friends, the Petrasch brothers, believed that there was something to his story, and they set out to find it. They spent weeks roaming the wilderness, searching for whatever they could find, which ended up being nothing. Julia Thomas did find a way to capitalize on the Dutchman’s fate, however. She drew up and sold some “treasure maps”, as well as told Waltz’s story to at least one freelance writer, who in turn embellished it even further.

  Hence, the story grew, and multiplied. And so today, there are almost too many “Lost Dutchman” stories of which to keep track. (And remember, it is the gold that was lost, not the Dutchman.)

  There are variations which include Mexican miners (who supposedly originally found the gold), Apache Indian raiders (who killed the Mexicans and maybe even Waltz’s sometime mining partner, Jacob Wiser), high-graded gold ore stolen by Waltz himself from near Wickenburg and stashed in the Superstitions, and even Jacob Waltz having murdered his partner to hoard the gold for himself.

  The wildness of the terrain, the relentless, blazing sun and lack of shade, the dearth of water in the remote desert canyons of the Superstitions, and a colorful cast of crazies, desperadoes, and dream-seekers who have over the years spent countless time seeking out the rumored riches have only added to the luster of the story.

  The details of all these legends and maps do not matter so much as the fact that they exist, and that the story of the lost gold endures – the fascination goes on. Over the years more than two dozen adventurers have lost their lives, in one way or another, while exploring the range.

Looking deep into the heart of the Superstition Wilderness, near Phoenix, Arizona. Weaver's Needle is in the background.

  The derivation of the name “Superstition” is not even certain. One version is that in the 1500’s, the Spanish explorer Francisco Vasquez de Coronado apparently gave the mountains that name, based on the Apaches’ claim that therein lay the abode of spirits, ones who did not look kindly upon intrusion, especially in the name of profit.

  Only a few years after Jacob Waltz’s passing, hard-rock gold was discovered not far from the north side of the range, near what is now the little mining town of Goldfield. Millions of dollars were taken from the ground during the heyday of mining operations there.

  That a true in-situ gold deposit does exist in the Superstitions themselves is very unlikely. As I’ve mentioned in the past, the range (in this case, the western end, of which is to where the legends refer) is built-up of thousands of feet of ancient volcanic ash, fused into thick, resistant layers which today have eroded into a maze of pinnacles, ridges, and gorges. Barren volcanic cinders – now rock – and that’s all. Barren of precious gold, that is, but not of dreams.

A maze of golden canyons makes travel through the Superstitions a true adventure. This view is from along the Apache Trail, aka State Route 88.

  Take a look at the Superstition Mountains from a distance, in the setting sun sometime. If you give pause for a moment, they look yellow, even golden. It’s that would-be coating of gold dust out there that you see.

  That and the glimmer in your eyes.

Turquoise Traders

Friday, October 14th, 2011

Mt. Chalchihuitl, in New Mexico.

  The drive through New Mexico had been long and tedious, and though I was tired, I was also excited to reach my goal. Just a few more miles, I thought to myself, and I’ll be there. This was to be the first of several places I had wanted to visit that are now known to be intimately tied to the history of turquoise in the New World.

  I was expecting the place I had been seeking to just jump out at me. But no, it turned out that it wasn’t that noticeable. Had I not been looking for it, I would have just driven on by, like the thousands of cars and trucks a day that zoom north and south between Albuquerque and Santa Fe, oblivious to the little group of small hills just east of the Interstate — another of those redundantly named places in the Southwest — the Cerrillos Hills. (Cerrillos means “little hills”, in Spanish.)

  Probably not one person in a thousand moving along that asphalt ribbon could have told you that in those barren looking hills is the oldest continuously mined site in North America. Like so many other places in our modern world where remnants of past greatness lie within reach of our everyday lives and yet go easily unnoticed and unconsidered, the Cerrillos Hills and their rich mines once shaped empires.

  The Indians of the Southwest, the Aztecs of Mexico, and later the Spaniards, would all come to know of this place and the treasure it once offered – the mineral we call turquoise.

  The world of gemstones is not just science. It also incorporates economics, psychology, art, and history. Especially history, since without tradition, there would be no real value to what otherwise would be just pretty little rocks. They’d be pretty, sure. But to have value, you have to have agreed upon tradition.

  Sometimes, as with diamonds, that tradition has simply been manufactured. Through intense advertising, for example, De Beers has created a tradition associating engagement, marriage, love, and eternity with diamonds. That very profitable tradition didn’t really exist before the twentieth century. I was searching for something much older, something not created by a marketing department somewhere.

  Turquoise is probably the oldest gemstone known. Its use in ornamentation goes back at least 7000 years. In the Americas, its place in history is vague, but, oh so intriguing. For with the continued evolution of our understanding of the extraordinary civilizations of North America, the history of turquoise is integral.

  That these hills are so unobtrusive serves as a kind of metaphor for the history of turquoise itself in the New World. When people in the Southwest think of turquoise jewelry, what undoubtedly comes to mind are large, clunky, elaborate pieces in which a multitude of blue stones are set into hand-worked silver necklaces, belts, and bracelets. The tourist shops and galleries of Scottsdale, Santa Fe, and Taos are loaded with them — some nice; lots of them junk.

  Most don’t realize that this style of turquoise jewelry is really a creation of the last one hundred and fifty years or so. Capitalizing on metal working skills learned from Spanish and Mexican artisans, Navajo, Zuni, and Hopi craftsmen started incorporating turquoise (from all over the Southwest, and now even Asia and labs in France where it is man-made) into silver jewelry. Railroads opened up the West in the late 1800’s, and the silversmiths’ creations found a ready market in the blossoming tourism business.

  Turquoise has one of those complicated chemical formulas that I was glad I didn’t have to memorize in college — a lengthy notation for hydrated, copper aluminum phosphate. We think of it as a blue stone, but green turquoise does occur also. Its composition is not nearly as interesting as its history, though, which goes way back beyond that of the 19th century Indians. Way, way back.

  By the way, our name for this gem, turquoise, is derived from a French phrase meaning “Turkish stone” — probably a reference to the fact that it was first imported into Europe by way of Turkey — its source in that case being mines in Persia, now Iran. Ancient Native Americans had their own name for certain highly sought-after green and bluish-green stones, turquoise among them. It is thought that also included with these gems were those we now call jade, and even poor quality emerald (remember, no one knew the difference between some mineral species until later science understood that they were different and had developed ways to tell them apart).

  For the most part, the earliest Americans apparently did not distinguish between blue and green hues. Both colors signified the same things: coolness, water, fertility. Within the Aztec pantheon of gods and goddesses, which of course evolved out of more ancient Indian beliefs, Chalchiuhtlicue was the deity of rivers and lakes, springs, and the sea. Her name translates as “She of the Jade Skirt”. Blue-green stones became known as Chalchihuitl, and from the association with water and life, they became symbolic, valuable, and objects of power within the shaman’s realm.

  Sources of the cyan-colored gems were varied, but through time one source became preeminent over all. We know it now as Mt. Chalchihuitl, somewhat centrally located in the Cerrillos Hills, and it is there that extensive prehistoric workings are found.

  For over a thousand years, turquoise mined there was carried vast distances by traders ranging over what became the Aztec empire and the outlying homelands of the Anasazi and the Hohokam. It became a basis for trade throughout the evolving cultures of the New World. Before the Spanish conquest, trade in Chalchihuitl would unite those native cultures in ways we are only beginning to understand.

  The Spaniards later laughed at the Indians’ love of the stone, for they were after what they considered to be treasures of much greater value: gold and silver. For those metals, the sacred mountain was a disappointment.

*********

 
Ruins at Chaco Canyon, New Mexico.

  Not more than several days walk from New Mexico’s Mt. Chalchihuitl lies an obscure canyon carved into brown, marine sands from the Cretaceous period. Wandering through the warm, tropical woods of those ancient times would have been the most famous of “terrible lizards”. Tyrannosaurus Rex and Triceratops fought bloody battles to the death there, while above nearby beaches soared evil-looking, winged reptiles — their narrow eyes fixated on the surf below, lest some tasty morsel go unnoticed. None of those creatures would recognize the area now.

  As you approach the canyon, its presence is not apparent. The view is one of flat table-lands — a desert of brush and scrub where struggling cattle simply maintain life from one day to the next. Only in the last few moments do you drop down and arrive among towering sandstone cliffs, and only in those last minutes does the feeling of the place supersede what the map portrays in such a dry manner.

  As I drew near the day’s objective, it took me by surprise, and it was another of those moments in life when I “got it”. This place is known now as Chaco Canyon. I literally couldn’t believe my eyes. I had seen pictures of it before, but they obviously hadn’t done it justice (just like my photo accompanying this article will not).

  I had read of its amazing ruins, and the dominance of its role in the Anasazi world of the time. And I couldn’t believe that I had waited so many years to come see it. It had just rained. A late afternoon thunderstorm had rolled through — thunder, lightning, and all — dropping the temperature by at least twenty degrees, and the desert smelled lush, lush. That only added sensuality to the scene, and as the low sun came out, and as the temperature rose again, I stood in awe of the setting spread out in front of me.

  What had possessed the old occupants of the enormous, walled, stone structures now lying there in ruin to build on that spot we will never know for sure. But it is one of those places where I am convinced that the power of the setting itself played a key role. We will also never understand what the residents of those massive buildings intended by living there, or what they called the place.

  But one thing we do know now is that the people of Chaco Canyon dominated the turquoise trade of their time. In fact, they may have been instrumental in developing it, and we also know now that the extent of their turquoise trade reached far into Aztec Mexico, and even to the heartland of the Hohokam civilization in what is now south-central Arizona.

  Present-day research shows us that the Chacoan Anasazi exploited the turquoise deposits at Mt. Chalchihuitl to a very great degree, and by way of a process called neutron activation analysis, we know that the sky-blue and cool green gemstones from the Cerrillos Hills made their way all over the American Southwest.

  Evidence uncovered during excavations at Chaco reveals that turquoise was likely traded for exotic birds from Central America, copper bells, and other treasures. Beginning at around 900 CE (Current Era), turquoise usage among the cultures of the region mushroomed, and this corresponds nicely with the rise and dominance of Chacoan culture. A vast system of engineered roadways radiates outward from Chaco Canyon, and it appears that it became the hub of a widespread turquoise trading network — its political influence even possibly based on the precious mineral.

  In diggings so far, over 200,000 pieces of turquoise have been recovered from the ruins of the “Great Houses” of Chaco Canyon. The Chacoans’ monopoly was not to last forever, though, and by 1300 CE turquoise had become common throughout the Indian communities of the Southwest.

  Was it just that major sources other than Mt. Chalchihuitl had been discovered? Had the Chacoans lost their edge in the trade? Maybe their power in the region had “gone to their heads”, and they had become self-centered and aggressive.

  Whatever the case, something sinister had started to happen. All you have to do is look around the region, even around the Valley of the Sun in south-central Arizona, and take note of where ancient settlements were being constructed — on steep, stark hilltops, on boulder-strewn and cacti-covered ridges, in places where no one in their right mind would build for the view alone.

  If you ever visit such now-crumbling ruins, one descriptive word will instantly pop into your mind: defensive. Were ripples of disintegration throughout Chaco culture being felt far and wide?

  Around 1300 CE the Great Houses of Chaco Canyon were abandoned. The turquoise mines of the Cerrillos Hills were quiet. And the deities of the blue gems of Mt. Chalchihuitl would have to wait for other servants.

*********

 
  With the demise of the Chacoan Anasazi seems to have come a general unraveling of cultures all over the northern highlands of the Southwest. Those traders of old had lost their political and social control of the region, as well as domination of the turquoise trade. The mines at Mt. Chalchihuitl would never again flood Mesoamerica with the blue-green gem of life.

  The high plateaus and mountains of New Mexico are not the end of the story, though, and I made my way towards home.

  In the 14th century, in the sprawling desert valleys of what is now south-central Arizona another civilization was just coming into its own. We now call these ancient people the Hohokam, which is a modern day Piman (Akimel O’odham) word meaning something like “those who have gone” or “all used up”. (Everyone who lives in the Phoenix area should at least be marginally familiar with their legacy. The city’s name owes its existence to early American settlers who realized the extent of the vanished society, and chose to rebuild on its ruins. Like the mythical Phoenix bird did after death, civilization there resurrected itself.)

  There is a lot that remains unknown about the Hohokam. However, many archaeologists do agree that they had more in common with the advanced civilizations of central Mexico (Toltec and Aztec) than any other Indian culture located in the geographic confines of what is the present-day United States. And the Valley of the Sun had likewise been home to one of the greatest centers of prehistoric civilization in North America, in terms of population.

  By some estimates there were fifty or sixty thousand people living in the area where Phoenix, Tempe, and Chandler now sit. They had devised and built a canal system which utilized around one thousand miles of canals to irrigate a body of land encompassing approximately a hundred thousand acres. That is about forty percent of what Arizona’s modern day Salt River Project now irrigates.

  From around 1300 CE, until their collapse at around 1450 CE, there is no question that the Hohokam dominated the Southwest — in cultural influence, food production, and trade. By some accounts, Hohokam-based traders may have ranged as far as Illinois, the California coast, the Yucatan Peninsula, and the Aztec capital of Tenochtitlan, now Mexico City.

  Agricultural goods, textiles, seashell jewelry, and turquoise would have been among their wares. Turquoise jewelry and carvings, once under the control of the Chacoans, had by this time become widespread throughout the Southwest. New mineral deposits of the gemstone had been found, too. Evidence now shows that turquoise was also imported into the Hohokam heartland from the Chalchihuites area, in Zacatecas State, Mexico (not to be confused with Mt. Chalchihuitl, in New Mexico). Other Hohokam turquoise artifacts have been determined to have originated from mines in what is now southern California, not far from Barstow.

  For decades, archaeologists have pondered the relative lack of turquoise objects among Hohokam ruins, and wondered why no evidence has been found of turquoise production facilities, or mining activity. Given the ancients’ propensity for trading, the sky-colored gem should be more ubiquitous in archaeological collections. What was lacking was the so-called “smoking gun” of Hohokam turquoise trade.

  Within the last decade, a site has been found in southern Arizona that just might be that “smoking gun”. On a remote hilltop, near modern day Tucson, sits the ruins of a place known in present-day Indian language as Na’Naksha’lKihhim — the “Village of the Scorpions”. Here are ruins of above-ground houses, a plaza, and a platform-type mound.

  Here, too, has been found evidence of turquoise processing and finishing, and now-spent mines. Although this particular site seems to have been abandoned while Chaco Canyon still dominated the turquoise trade to the northeast, it shows a clear connection to lands further south and is proof of the Hohokam presence in the turquoise trade. If all is as it appears here, the fusion of the civilizations of central Mexico with the Hohokam comes alive through turquoise.

  It was near sunset, and I stood there next to my idling car in the flat wastes, momentarily stopped on the shoulder of yet another roaring modern-day artery of trade. Wheeled vehicles whizzed straight from one horizon to the other. With every one that passed, a blast and thud of wind shook me and pushed me off towards the chaparral.

  Diesel fumes and automotive exhaust overpowered the nearby sweet smell of warm creosote — fading, then returning after each pulse of traffic. I could see purplish ridges and volcanic rock spires in the distance to the west, the landscape of the Village of the Scorpions, and momentarily, I daydreamed about life in the way-station on a trade route now vanished.

  I’ve noted above that what most people think of, when turquoise jewelry is mentioned, are the big, somewhat geometrical, multi-stoned silver ornamentations of the Navajos and Zunis, and that this style is only a recent invention.

Tesserae-style turquoise and shell jewelry.

  The real styles of the native, older occupants of the Southwest include beads, pendants, carved animal and bird motifs, and pieces composed of turquoise and shell tesserae. Tesserae are like little tiles, and were glued with pine resin to shells or wood pieces. This mosaic type is present in Aztec art as well.

  Pictured here is an ancient piece of turquoise jewelry, in the tesserae-style. This piece is a pendant with a small, reddish, center tile of shell, and measures about 9 centimeters (about 3.5 inches) across. While the pictured pendant is not Hohokam in origin (it is from the White River area in eastern Arizona), it is the closest thing I could find to photograph to show the style. It does date from approximately 1200 to 1400 CE.

  Trade routes shift, civilizations come and go, the world becomes ever more complicated and fast. But concepts of life, fertility, and coolness (especially in Arizona) linger — they remain, as does the stone that has come to symbolize them.

  True tradition never dies. It just changes hands, that’s all.
 

Touchstone

Thursday, September 8th, 2011

Basaltic Moon Hill, as seen from Shaw Butte, looking northwest, in Phoenix, Arizona.

  Rocks arouse feelings. All we have to consider are gemstones to realize that. Though they are small, the power they exert on the wearer, or even the bestower, is legendary. You can make the case that a stone’s power is constructed by advertising, using diamond as an example. Or you can look at an ancient stone like turquoise, for instance, and mull over the probable connections the ancient Hohokam people in our Valley made between it and the sky, water, or coolness.

  Big rocks elicit feelings, too, I think, and I mean big rocks that form things like cliffs, hills, and mountains. One of my favorites is the rock known as basalt.

  Not long ago, I was trying to “get a feel” myself for what basalt evokes. I was driving around Moon Hill (pictured, from Shaw Butte), that little ridge that lies just north of Thunderbird Road, on the east side of I-17 and 19th Avenue. My attempts to go up onto it were to no avail, however, as every road was gated. I probably could have waited at a gate, and slipped through behind someone else’s car. But then if asked, how would I explain what I was doing there? “Yes, sir. Who? Me? Oh, I’m just here feeling the rocks.”

  “Rrrright,” would undoubtedly be going through the mind of my inquisitor.

  Melancholy, mild foreboding, and loneliness are some of the feelings I’ve seen in myself around basalt in other places. I had really wanted to go door to door on Moon Hill, from home to home (and I could see some nice ones up on top), and ask people what they feel living there.

  Maybe someday I will get that chance. It has got to be different from what people living on Camelback Mountain (mostly granite) feel, for example, or from what people around Squaw Peak (mostly schist) sense. That feeling would have nothing to do with the view, or the facing direction.

  This kind of thinking is, by the way, off the scale for most geologists. But not all. There are those of us of a scientific bent that are open to the subtleties of nature. As one old saying goes, “the devil is in the details.” So are the good spirits, I think, and much of the beauty. Illustrating this view of nature, the Japanese have ways of classifying rocks that are unheard of in our Western culture, and I have pursued this subject in other writings (see “First Impressions”).

  Basalt (say buh-SALT, not BAY-salt) is a very dark, heavy rock. When molten, it flows easily. It covers many of the hills along what we call the Black Canyon Freeway (I-17) between Phoenix and Black Canyon City. Along the road you can see black rock, sort of “dripping” off the edges of the hills.

  That look is simply the result of the basalt breaking up into chunks and fragments that roll and slide downslope because of erosion. The solid rock itself forms very resistant flat caps or layers on much of the higher ground north of the metro area, creating scenic backdrops such as New River Mesa and Skull Mesa (mesa means “table” in Spanish).

Basalt

  Around fifteen million years ago, deep fractures opened the crust of the Earth in the area north of Phoenix, and from within erupted the fiery liquid that then cooled and now covers Moon Hill. The basalt flows in central Arizona are some of the youngest rocks around us. I know, fifteen million years sounds like a long time ago, but it is not, really. Earth is 4.6 billion years old. Fifteen million years represents just a third of one percent of its history!

  I was curious as to the origins of the rock’s name, which was not an easy subject to track down. Apparently the Romans took the name basaltes from the Greeks, who in turn got it from the Egyptians, and it seems to have meant “touchstone”. Another source I saw attributed the word to unknown African sources. But then, Egypt is in Africa.

  The Hawaiian Islands (not an easy place to feel melancholic, I admit) are made mostly of basalt, as are the plains of eastern Washington State (an easier place to be depressed), the Snake River Plain that runs across southern Idaho, and the dark splotches that we see on our moon overhead.

  It covers the seafloors, and if you drive north from Flagstaff towards Page, you can see great long tongues of basalt, now mostly covered by brush, emanating northwards from the San Francisco Peaks, running for miles along Highway 89. In the back-country on the way to Puerto Peñasco (Rocky Point), in Mexico, are some of the most amazingly picturesque basalt flows I have ever seen.

Recent basalt flows cover the desert north of Rocky Point, Mexico.

  Next time you see some, get out of your car, approach it, spend some time, and see what you think. Or more importantly, what you feel.

Colors in the Sun

Friday, August 12th, 2011

Bright blue pebbles catch my eye. Is it turquoise?

  I was sitting low in the hot tub the other day, my mind wandering and drifting about like the palm fronds in the gentle breeze above me. It is where I get some of my best thinking done. No pressure, no distracting phone calls, no emails beckoning me from the cathode ray tube that is usually in my face.

  As is usual on weekday afternoons, there was no one else around. The sun was intense, the dry desert air invigorating, lightly scented as it was with the warm pungency of chlorine. The bubbling of the Jacuzzi added to the stimulation, and its gentle massage coaxed me to just relax, and let the thoughts flow.

  I am lucky enough to live in a place with a very attractive swimming area and spa. Sometimes when I walk over to the pool, with its tiles colored like turquoise and lapis lazuli, I am taken aback by its soothing effect – the cool blue somehow so easily mitigates the fierceness of central Phoenix in the summertime. Once in a while, when I’m in the tub, someone will walk by me there and remark “how can you stand being in that thing when it’s 114 degrees out?” I point out that it is cooler there than the air, and that usually shuts them up. A small observance, yes, but significant.

  So it was in that vein when I looked over my shoulder and noticed a little gathering of rocks that someone had left sitting just by the edge of the bath. There they had placed a handful of pebbles, all reddish-brown, but tinged with bright blue coatings, and they glowed intensely against the glaring ivory colored background of the pool deck. They hadn’t been there long – some were still wet – and I guessed that some child had gathered them from nearby, had been playing with them in the pool, and then, as children do so easily, simply became distracted and forgot them there before leaving.

  I wondered why they had not registered more in my own mind when I had arrived. After all, I had to have literally stepped over them to get into the tub. “That just goes to show you,” I thought to myself, “so busy thinking, mind all cluttered up, I didn’t even notice.” Sitting in the bubbling waters had changed that. And then I had another thought: here is a metaphor right in front of me (or actually behind me, in this case) of the beginnings of jewelry, the very business I am in!

  No one knows when humans first started using stones for decorative purposes, but we do know it was a long time ago. Drawings on cave walls showing humans with body ornamentation are believed to be at least 20,000 years old. People used a variety of things to decorate themselves: feathers, seeds, insect wings, and stones.

  Far, far back into human history, someone somewhere was walking up a streambed or dry wash (most likely), and saw some pretty rock lying in the gravel at his or her feet. They reached down, picked up the attractive rock, and from that moment on, it was special to them. Maybe they took it home and set it on a shelf next to the hearth. Maybe they decided to drill a little hole in it, put a string through it and wear it, or maybe they just set it aside there near where it originally lay, as if to proclaim, “this is special – I’ll give it its own spot.”

  The tradition goes on today. Kids (and lots of adults) all over the world pick up pretty rocks, for whatever reason – the main one being that that stone is special to them. The stone has just received a little dose of power – a power of influence on that person’s life (and maybe others).

  You see the same thing now in jewelry all around us, in whatever form. Some people wear crystals or carved stone amulets to ward off perceived evil or gain good fortune. Some people wear gemstones as a symbol of home, or history (think: grandma’s diamond ring). Lots of people wear them as a symbol of wealth and prestige (all you have to do is watch the Academy Awards on TV, with glamorous actresses decked out in diamonds galore remind yourself of that!). Even more wear them as a symbol of eternity. De Beers has been very skillful at cementing together diamonds, love, and forever.

  Gemstones and their uses so surround us, and are so common in all their forms, that people tend to forget that they come from the Earth. They are creations of nature (except for those nowadays that are altered, dyed, treated, repaired, irradiated, or synthesized!).

  I have actually seen people look surprised when I remind them that the diamond they are looking to purchase may not exist, or at least may not be easily found in the marketplace. Want to buy a three carat, natural, blue sapphire from Montana’s Yogo Mine? Good luck. There are only a few in existence. Don’t blame the jewelry trade. Blame Mother Nature and the volcanic rocks of central Montana for being so stingy.

  “Uh, oh,” I thought. I was starting to feel “well-done.” Time to get out of the water. All these realizations had totally absorbed my attention, and time had passed by quickly. The sky-blue and celadon-green stones assembled there in the sun were not turquoise, I knew, unfortunately.

  I had had my hopes high for a moment, but knew too much about the geology around Phoenix for that to be the case. Chrysocolla is the name of the look-alike. It’s a copper mineral, too, but this stuff is too soft and thin to use for jewelry. The landscaping company gets its rock from formations around the valley where slight copper mineralization occurs. Look in your backyard – maybe you have some of the same.

  I climbed out, toweling myself off, and glanced at the gravel beds from which the palms around the pool grew, and there, sure enough, were other turquoise-hued fragments calling out from the reddish, chipped landscaping pebbles. As many times as I had been to the spa, I hadn’t noticed them before. Hot tubs work wonders.

Geology Upside Down

Monday, May 9th, 2011

Four Peaks,on the skyline east of Phoenix, Arizona.

  Dominating the skyline east of Phoenix and Scottsdale, Four Peaks is one of the most recognizable of central Arizona’s mountains. Locals consider it to be one mountain, so I won’t say “Four Peaks are …”. It’s one of Arizona’s landmarks for which little pondering is required as to how it got it’s name! (In the photo above, Four Peaks is in the distance behind the closer Goldfield Mountains.)

  Geologically, it is a piece of landscape art, and the way it formed is almost counterintuitive. You might think that the four summits we see so easily are big piles of rock that were molded into shape on top of the older, lower slopes. But that would be wrong! The rocks of those four summits were there first. Then the granite below was added.

  How, you might ask, could that be? Well, the makeup of the Earth’s crust is a complicated thing, and is not always what it seems. Geologic time, and the forces that have moved things around throughout the history of the world, always seem to combine to give us an interesting story.

  If you drive out the Beeline Highway (SR87), by the time you are about 15 miles from Fountain Hills you will be near Milepost 200, and you will be looking at Four Peaks on your right (east). Even better, go to near Milepost 204 and turn onto the gravel road marked “Four Peaks”, and you can get a few miles closer. You’ll be able to see that the mountain is basically made of two rock formations. One is a continuation of the bedrock you may be standing on: granite. The other forms all four of the peaks. The dividing line between these rocks is more or less where the slope breaks, just below the notches between the peaks.

  About 1700 million years ago, during what we now call Precambrian time, our area lay on the edge of an old continent — an area probably much like today’s Gulf Coast near New Orleans. All of the sand and muck that came down the big rivers from the interior got dumped into a big basin, like the present-day Gulf of Mexico. There it piled up, got buried, eventually hardened, and was baked into thick, resistant layer or slab — very hard rock we call quartzite.

  Several hundred million years later (not really a long time in geologic terms) the immense forces that constantly reshape the Earth’s surface crumpled the land and its many rock formations from side to side, pushing up great mountain ranges that actually extended all the way over to where today’s Great Lakes are. Geologists give this little event a nicely sensual name — the Mazatzal Orogeny.

  During all of that pushing and shoving a lot of the rock below was very hot. Molten granite, in fact, and here’s where the art work comes in. For whatever reason, in the area of the future Verde River Valley, the underside of the above-mentioned quartzite slab was very unevenly shaped. Maybe it started out that way; maybe it got shaped by the pushing action of the molten rock, pulsing up from below. The result, in any case, was that monstrous chunks of the quartzite now hung down into the granite. Four of them.

  Granite erodes away more easily than quartzite. It breaks down into crumbly rock grains, some of which those of us who hate mowing lawns use for landscaping around Phoenix. So the granite around the four big masses of rock slowly wore away, down, down, into rolling hills and slopes and surrealistically shaped boulders that make the Beeline such a scenic drive.

  The four big peaks towering above the trip to Payson even have a geologically technical name: roof pendants — remnants of a much more vast layer of quartzite; a layer of one-time mud and beach sands and sea-side days gone by.

4 Peaks Amethyst gemstone  These big pendants give rise to little pendants — sparkling, beautiful little pendants in the form of the vivid purple gemstones we call Amethyst, mounted into jewelry (yes, not only pendants, but ring stones, earrings, and all other wearable forms).

  You see, up there on southernmost of those peaks, is one of Arizona’s (and America’s) treasures: the Four Peaks Amethyst Mine. Deep inside the quartzite, and way in the past, networks of fractures formed where quartz-rich solutions grew beautiful quartz crystals.

  Quartz is a mineral composed of silicon and oxygen, and the purple variety is called Amethyst. The crystals are now mined and cut into gems, which in this case are considered to be within the world’s finest grade of amethyst.

  You can even wear one — a little pendant cut from a very big one!

 Author’s note: Besides being very inaccessible, the Four Peaks Amethyst Mine is on private property and is completely closed to the public.

Jewel Box

Wednesday, April 27th, 2011

A pegmatite in the Sierra Estrella, southwest of Phoenix, Arizona.

  Cutting the sky southwest of Phoenix is the jagged, long ridge of the Sierra Estrella — it dominates the Valley of the Sun. Yet, it is less well known to locals than many smaller, less imposing ranges here, and I will bet that most Phoenicians couldn’t even name its more prominent peaks.

  I had just set forth up its southwest-facing side — the side opposite from town — and had just barely started along the trail when I was greeted by fields of glitter along the ground’s surface. Multitudes of bright flashes caught my eyes, making a rich scintillation amidst the chollas, saguaros, and ocotillos growing in profusion along those lower slopes.

  Up to that point, the only thing on my mind had been one thought: what a workout this was going to be. A look up at the high summits above me, one of which was my destination, had convinced me that it was going to be a long, long, sweaty day. Although I was on my way up to one of the less conspicuous points along the sawtooth-like crest, I had heard that this trail was one of the more spectacular hikes in the Estrella Mountains — one not to be missed.

  Reaching down to grab one of the sparkles, I saw right away that it was a flat, shiny leaf — but not a leaf of vegetation. Rather it was a thin leaf of stone — a piece of a mineral known as mica — that was beaming back at me. Its lustrous surface had captured the strong light of the desert sun, throwing it right back into my face.

  And I was delighted with that, as I knew that this mineral, and the way it lay strewn all over there in numerous fragments, meant that somewhere up above me, on those steep, rocky cliffs of the Estrellas, was a pegmatite, an example of a rock formation sometimes known as “Nature’s Jewel Box”.

  Right up my alley, I remember thinking. A hike through gemstone country! A treasure hunt, even. Well, not quite, it turned out, but it was close. All that was missing were the gems and jewels (saleable ones, at least).

  By the time I saw it, I was dripping wet and breathing heavily. I was not sure which smelled more strongly: me (probably), or the pungent, desert brush all around, baked dry by the hot, unforgiving sun. There before me, crowning the mountain, was a great outcrop of quartz, white and glassy, looking like a chunky snow-bank, gleaming with the same sheets of mica that I had seen down in the valley.

  If you want to go gem hunting, finding a pegmatite is a good way to start, for pegmatites are rock formations where gem minerals are frequently found. There are other places in and around the Valley where such rock structures also occur. “Swarms” of them are to be found in the Hieroglyphic Mountains, and even Mummy Mountain plays host to some mineralogically-rich ones.

  Imagine a gigantic body of molten rock, granite in this case, deep in the Earth’s crust. As it intrudes into the rock surrounding it, it forces fractures to run through the enclosing hard stone. Into these fractures flows more molten rock, composed of minerals which are more mobile and volatile — distilled, so-to-speak, off the parent mass.

  This “liquor” of fluid rock then cools slowly into a solid, dike-like pattern of large crystals — a pegmatite. Later, when it gets exposed by erosion, its concentration of sharp, angular forms reveals the mixture of segregated minerals within — in this case, quartz and mica.

  It was these large mica plates, weathered and washed out of the formation, that I was seeing along my route. They make excellent reflectors. But no emeralds or sapphires here. (I had kind of figured that.) Otherwise, there would have been a mine here, probably a very old mine, as pegmatites have been known since ancient times as good places to find large crystals of beautiful and rare gemstones.

  I struggled to the very top of the rocks, where the view was breathtaking. In the distance was the metropolis of Phoenix. I could see its downtown skyscrapers, and several snake-like freeways winding through the Valley’s maze of crisscrossed streets and avenues.

  I recognized Camelback Mountain, readily distinguished by its reddish profile, and beyond I could even see the McDowells and the far-off Mazatzal Mountains. Once more grateful that I’d achieved my goal — this time with the added bonus of some unexpected beauty along the way — I sat there on the immense white, dazzling, hard exposure of almost pure silica, and had the quick thought that it was a wonderful place to get a good, all-around suntan, too.

  A little closer to the sun, and heaven, you know….