What is Fool’s Gold?

Fool’s gold is a mineral called pyrite, also called iron pyrite. Its name comes because it fools people into thinking they’ve found genuine gold.

“Pyrite is usually found in quartz veins, sedimentary rock, metaphoric rock even igneous rock. It has a very cubic form and a nice brassy luster, so it’s confused for gold a lot. There aren’t too many things out there that look like gold besides gold,” said Michael George, Assistant Chief of the Nonferrous and Precious Metals Group in the Mineral Commodities Section of the National Minerals Information Center of the U.S. Geological Survey.

George has been with the USGS (www. usgs.gov) for almost 20 years. He earned his bachelor’s degree in mineral economics from Penn State and his master’s degree from George Mason in geographic and cartographic science.

How Fool’s Gold Differs From Real Gold

Looking at it from a scientific standpoint, fool’s gold and real gold aren’t alike at all.

“Chemically, pyrite is made up of the chemicals iron and sulfur where gold is its own element. Gold only has molecules of gold in it. Pyrite has one iron molecule for every two sulfur molecules. Their chemical compositions are completely different,” explained Cynthia Pridmore, a California Geological Survey (CGS) Senior Engineering Geologist.

Pridmore has spent 33 years with the CGS. Although most of her work has primarily been in earthquake hazards, because gold is California’s state mineral, she feels it’s something all employees should know about.

“Gold doesn’t really have a form, it’s pretty much an amorphic blob when it’s found in nature,” added George. “While pyrite usually has a cubic structure, it usually has flat edges on it. If you see something with flat edges and shiny, you’re pretty much guaranteed that it’s pyrite.”

Simple Tests to Tell the Difference

There are several simple ways to tell the difference between fools’ gold and the real deal. One quick way to tell is if you bite it and it hurts, it’s not gold. However, this test isn’t recommended if you want to keep your teeth!

“This kind of goes back to when you’d watch old movies and you see the gold miner bite on the gold nugget and says, ‘Ah, that’s real gold,’ that’s because he’s denting it with his teeth,” she said. “The gold nugget is going to be soft enough that teeth will dent it. However, if you bite on too many rocks that aren’t gold, you’ll start wearing your teeth away.”

Hardness, however, is one of the easiest tests, but Pridmore has a better solution than the old bite test.

“If you take a metal probe or metal fingernail file or anything that has steel in it and you touch gold, it’ll deform. Kind of like a ball of aluminum foil kind of crushes,” said Pridmore. “Gold is malleable, it’s soft and it can dent easily. If you don’t want to dent it too much, you can dent it lightly and look at it with a hand lens to see the dent in it. The hardness is really important. Pyrite is brittle. You’ll either scratch it or you’ll chip off a piece of it.”

She said another easy way to tell the difference is in color. Pyrite is often described as brassy, but it has a bit of greenish color in it when compared side by side with gold. In the field, you can compare your find to a piece of gold you’ve already confirmed as genuine, like a wedding band.

Both Pridmore and George agree that shape is also a reliable way to tell the difference between fool’s gold and real gold. They both describe pyrite’s shape as cubic. George also describes the edges as straight, while Pridmore describes the crystals of the pyrite as usually being at right angles.

When asked about the most accurate ways to distinguish pyrite from gold, Pridmore suggested panning and George described a fun streak test.

“Gold is heavier than pyrite,” Pridmore said. “If you break the substances up into a fine material and pan it, you’ll see that the heavier mineral is what’s left behind. Pyrite isn’t that heavy, so it’d get flung out of the pan.”

George added that “in Geology 101, we’re taught what’s called the Streak Test. If you take a chunk of pyrite and rub it against a white unglazed porcelain tile, it’ll streak black. It’s very noticeable. But if you use gold, it’ll leave a light yellow streak. All you’re doing is transferring the gold onto the porcelain. It’s really easy to tell. This is a fun test. I used to go to elementary schools and do geology talks, and this was always a fun one to show them. You don’t expect it to happen.”

Other Minerals That Might Fool You

It’s not just pyrite that can fool a person.

“Besides pyrite, sometimes people mistake weathered mica for gold, which is a flaky mineral. But mica is only mistaken when it’s weathered because it’ll usually catch the sunlight. If you see it at a certain angle, it’ll catch the sunlight and reflect back maybe yellowish hue. However, once you get close to it, you’ll clearly note that it’s not gold. It just looks like a flake, like Formica,” said George.

While pyrite (fool’s gold) is the most common mineral mistaken for gold, chalcopyrite also appears and looks like gold, but it’s also brittle and not soft like gold. Weathered mica could look like gold, particularly when you’re panning.

“If you do see gold, you’ll see that little bit of grain in the bottom of the pan with the heavy dark minerals. But mica is sometimes in there, too, because it’s flat and it floats around,” said Pridmore. “Kids get really excited, especially if you’re at the river and you stir up the sand, and you see all those things twinkling at you, that’s mica. It can look like it’s flashing gold at you, but it’s not gold. It scratches very easily. If you take a little metal probe and scratch the mica, it’s brittle. It’ll scratch, but it’ll scratch in crumbs and break into powdery pieces. Whereas gold, if you poke it, it’s going to be soft and not break.”

What’s Pyrite Worth?

Much of the information you find on pyrite declares the mineral relatively worthless. However, that doesn’t mean it’s not used for certain things that can give it some value.

“Back in the ancient times, it was a useful thing to find because it would spark so it was used a lot against steel to start fires. Now, not so much,” said George. “Domestically in the United States, we don’t use it for anything other than pretty rocks, which I guess is a useful thing,” he said. “You’ll often see it as an ornamental rock on somebody’s desk. I’ve got several pieces in my office. It does look nice and pretty.”

Elsewhere in the world, pyrite is used to produce sulfur dioxide to make sulfuric acid. Sometimes it’s used in the fertilizer industry.

Armed with these details on fool’s gold, you should be able tell if those shiny specks are truly gold that’ll put a little cha-ching in your wallet.

This story about fool’s gold appeared in Rock & Gem magazine. Click here to subscribe. Story by Moira McGhee.

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How Does a Fossil Become Pyritized?

Once a marine creature dies and is buried by sediments, generally storm deposits, it begins its transformation from a normal seashell to a pyritized beauty.

When a fossilized shell is pyritized, the original calcite shell is replaced microscopically by filling the cellular spaces with minerals, in this case, iron pyrite. Organisms may become pyritized when they are in marine sediments that are saturated with iron sulfides. (Pyrite is iron sulfide.) As organic matter decays it releases sulfide which reacts with dissolved iron in the surrounding waters. Pyrite replaces the carbonate shell material because of an undersaturation of carbonate minerals in the surrounding waters.

What is a Brachiopod?

Brachiopods are marine bivalve mollusks. A mollusk is a soft-bodied invertebrate animal with hard external calcium carbonate shells called “valves.” Commonly they are called seashells or lamp shells because of the shape of the valves. Although most brachiopods are extinct, a few may still be found around the world.

The word brachiopod comes from ancient Greek, “brachion” meaning arm and “podos” meaning foot. Brachiopods have a large muscular “foot” they use to anchor themselves to the seafloor.

Brachiopods arrived on the scene during the Silurian period and most ranged through to the Carboniferous period. When found in deposits they are generally abundant. There are a few locations where the sediments contain millions upon millions of fossilized brachiopods.

The outer shells have many fine ridges called costae, running from the bottom or back of the shell to the front. Brachiopods have hinged shells at the top and bottom, clams have a hinge with a left and right arrangement.

Some brachiopods are “inarticulate” and do not possess hinges, but most have a “stalk-like” pedicle or foot that projects from an opening in the bottom valve. That pedicle keeps the animal anchored to the seafloor.

Paraspirifer Bownockeri

One of the most famous brachiopods is from northern Ohio called the parsapirifer bownockeri. These are getting harder and harder to find…especially pyritized.

The Devonian Silica Shale from Lucas County in Northwestern Ohio produces many kinds of brachiopods and some are bedazzled with pyrite crystals. The bownockeri species is a large brachiopod reaching a maximum of three inches in length. It is believed to have inhabited shallow mudflats.

Sitting on its pedicle valve, it was a filter feeder filtering the water for bits of floating plankton and detritus.

The Silica Shales of Lucas County, especially near the city of Sylvania, are well known for pyritized fauna such as paraspirifers, Atrypa brachiopods and bryozoans. Many of these golden beauties reside in older collections. They are no longer readily available as the quarries have shut down or have denied access because of mining regulations or fears of litigation. It is sometimes still possible to purchase these in local rock shops and rarely at rock shows.

This story about pyritized seashells appeared in Rock & Gem magazine. Click here to subscribe. Story by Joseph “PaleoJoe” Kchodl.  

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The Organ Mountains are one of the most stunning ranges in New Mexico. Anyone driving past Las Cruces on Interstate 10 will have an excellent view of the mountains. The granitic core of the range forms a jagged, sawtooth pattern east of the Rio Grande. Early Spanish explorers thought they resembled the organ pipes of European cathedrals, and the mountains were referred to as Los Organos, or the Organ Mountains.

Like all mountain ranges in New Mexico, the Organ Mountains were painstakingly explored by prospectors searching for gold and other metals. Virtually all near-surface deposits of metals were discovered quickly and mined if they had enough ore. The Organ Mountains were no exception, and several former mines lie along the flanks of the mountains.

While the Organ Mountains have several former mines, many are inaccessible for mineral collectors. Much of the eastern side of the Organ Mountains is part of White Sands Missile Range, and it is not possible to access any mines in this area. Private land and fences also block access to many of the mines that are not within the Missile Range. Many of the mines that remain accessible can take considerable effort and time to reach.

Turning to Mine Memoirs for Information

Fortunately, there is an area just north of the Organ Mountains that has some easy-to-reach mine workings with collectible minerals. This is the area of the former Memphis mine, which is just north of U.S. Route 70 and northeast of the town of Organ. The mine lies along the foothills of the San Agustin Mountains, which are just north of the Organ Mountains. The USGS topographic map for the area, which is Organ, New Mexico, indicates there are three shafts in the area of the mine.

One of the best references on the geology of the Memphis mine area is Memoir 36 of the New Mexico Bureau of Geology and Mineral Resources. “This is Geology of the Organ Mountains and Southern San Andres Mountains,” by William Seager, and it was published in 1981. This outstanding guide is available at https://geoinfo.nmt.edu/publications/monographs/memoirs/36/. This download is extremely useful since it also has the geologic maps that go with the report. Many online reports only provide the text and do not have key maps.

The Memphis mine reportedly produced $200,000 to $400,000 worth of copper, zinc, and silver during its operation. The deposits are described in Seager’s paper as replacements of west-dipping strata of Lead Camp Limestone adjacent to the Sugarloaf Peak quartz monzonite porphyry. The Lead Camp beds contain ore at four different horizons, separated by marble or barren calc-silicate rock, which Seager referred to as garnetite. The deposits are tabular and dip west about 40 to 70 degrees, and have been explored by open cuts, shafts, and drifts to depths of about 200 feet. The primary ore minerals were chalcopyrite, sphalerite, and malachite, while azurite, chrysocolla, and hemimorphite formed in the oxidized zone that extends to the bottom of the workings.

A large body of chalcocite was also reportedly found at shallow depths in the easternmost ore horizon. Gangue minerals, which are waste minerals extracted with the ores, are mainly quartz, pyrite, hematite, and “especially garnet.” The mention of “especially garnet” is worth noting, as this indicates that garnet is likely a common mineral that can be found at these workings.

The area is also described in detail within a Geology M.S. thesis by Thomas Glover from the University of Texas at El Paso. This thesis, dated 1975, is entitled “Geology and Mineral Deposits of the Northwestern Organ Mountains, Dona Ana County, New Mexico,” and is available as an open file report from the New Mexico Bureau of Geology and Mineral Resources at https://geoinfo.nmt.edu/publications/openfile/downloads/0-99/63/ofr_63.pdf.

Formation Studies Draw Debate

Glover described the mineralization as occurring within the Permian Hueco Formation. The Lead Camp limestone described as the host rock by Seager can be considered to be within this formation, even though there is still debate over the stratigraphic nomenclature for the region. Glover noted that the garnet was andradite, which is an iron-rich garnet, and that diopside and wollastonite also formed as replacement minerals during the pyrometasomatic stage of mineralization. Glover described three shafts at the site, which he listed as the Roos, Zinc, and an unnamed small shaft. He said the main ore minerals were malachite, azurite, chrysocolla, and complex sulfides, and he also noted that chalcocite and massive sphalerite were also encountered in the Roos and Zinc shafts, respectively. The Roos, Zinc, and a small unnamed shaft are apparently the three shafts that are shown on the Organ, New Mexico, topographic map.

Another source with information on the Memphis Mine is also one of the earliest publications on the Organ Mountains. This is “Geology of the Organ Mountains,” which is Bulletin 11 of the New Mexico Bureau of Mines and Mineral Resources, by Charles Dunham.

The bulletin was published in 1935 and is available at https://geoinfo.nmt.edu/publications/monographs/bulletins/downloads/11/Bulletin011.pdf. Dunham said that the Memphis Mine was discovered prior to 1882 and that a small water jacket smelter was operated on the property. The last work was completed between 1927 and 1929 by the Memphis Corporation. The geologic description is consistent with the information reported by both Glover and Seager.

Before going to the area I also checked the land status of the area using the Map Viewer for U.S. Bureaus of Land Management (BLM) administered land in New Mexico, which is available at https://www.arcgis.com/home/item.html?id=7c417fa0eab24661bd5050c3113c580d. This mapping is based on BLM information and it is actually provided by ESRI.com. The map showed that the area has both land that is administered by the BLM land and private land.

Visiting the Memphis Mine

BLM-administered land is generally open for mineral collecting, as long as it does not have any active claims. Private land may or may not be posted, and it is often difficult to determine private land in former mining districts if the areas are not clearly fenced or posted as such in the field.

I first visited the site of the Memphis Mine in late December 2013. I visited the area with my brother-in-law, Mike, and my son, Daniel. We did not have a four-wheel-drive vehicle so we parked on the north side of County Road D087 and hiked to the mines. There were no gates, fences, or other signs indicating that mineral collecting or access to the mines was not allowed, and the boundaries of private land were not marked or fenced. We did not see any indications of any active mining claims. This hike to the mines was a short walk and we were soon on top of several mine dumps. We did not see any rattlesnakes, but it was undoubtedly too cold. This place will likely have a lot of snakes when the temperature is right.

The area had some concrete foundations, which must have been the foundations for the former mill or water jacket smelter that was reported to be on the mine site. The dumps had an abundance of minerals, and there were several signs of previous rockhounds, such as freshly broken and piled rocks. I noticed an area near the foundations that was covered with an abundance of white rocks, and closer inspection revealed these were pieces of coarse white marble. Much of the marble was nearly snow white. In addition to the marble, I found several pieces of coarse calcite.

Some of the other dumps had garnet-rich rocks. Most of the garnet was massive, but some small individual crystals could be found with some effort. The garnet was generally light brown to light green, which is typically the color of andradite. The rocks were extremely hard, and it was often difficult to break off the garnet-rich sections.

Some of the dumps had a lot of oxidized hard rocks that were mostly dark brown limonite. They were dense and had a high iron content. Malachite was also common on the dumps. The malachite was generally light to dark green and formed as a crust or coating on the rocks. Many of the rocks also had coatings of light blue chrysocolla. However, I did not see any deep blue azurite. I thought this was a great place to see garnet, marble, and malachite, and it was easy to reach from the highway.

Returning to Memphis Mine

We returned to this area on January 1, 2018. I came with my son, Daniel, and my daughter, Roberta, who were 23 and 21, respectively, so I was fine with them walking around the site. This time we had a rental four-wheel-drive Grand Cherokee SUV, and we were able to drive into one of the access roads to the site. There were still were no signs or any gates in the area of the mines. We drove about 500 feet on the access road and parked the car in a safe location. The road quickly became rough and I had no interest in damaging my rental car, which I have done on previous New Mexico trips.

The area was much the same as I remembered it from 2013. We walked past the old concrete foundation up to the mine dumps. The shafts were either caved in or had a wire screen across open holes.

The area of white rocks was still present, and I was able to find some nice pieces of coarse marble and some calcite. Some trace malachite was also present in this area. I soon walked up to the other dumps just south of the white rocks. The area had some relief, and the hiking was minimal, but it did not involve much distance from our vehicle.

During my first visit to this area, I saw some garnet near the mines to the south, and I hoped that could see some more again. The second time around I quickly found many examples with garnet. The crystals were not large, and much of the garnet was massive instead of individual crystals. The garnet was generally a resinous brown, but some of the garnet was also light green. We also found much more malachite on this visit as well. Most of the malachite appeared as surface coatings on the rocks and ranged from bright to light green.

Patent Mine Basics

After we finished at the Memphis mine and surrounding area, we drove north on County

Road D078. I saw some additional mine workings to the northwest, and we wanted to see if we could get to these workings. We were able to drive most of the way, but the road soon turned into a sandy arroyo, and I thought it would be better to park and walk. Some of the bushes on the arroyo brushed up against my car, and this can also cause considerable and expensive damage to a rental car. We then hiked to the mine dump on the side of a long hill.

This mine is reportedly the Homestake mine, based on the maps in Seager’s 1981 paper. This area also did not have any fencing or indications that it was an active claim. What it did have was lots of trash and signs that it was used for shooting. There were several shell casings and items that were riddled with bullet holes, so it was obvious that other people frequented the area, but for reasons other than mineral collecting.

Despite the mineralogical description of the Homestake mine, we did not find any minerals here. This was surprising as the workings were extensive, based on the size of the mine tailings. The minerals were much better at the Memphis workings. The Homestake mine is only worth a visit if you want to confirm for yourself that no minerals are present here or if you are in the mood for target practice.

According to the BLM map referenced earlier in this article, much of the area is on BLM land, but the two southernmost shafts shown on the USGS topographic map are marked as private land and this may be part of a patented mining claim. Information from Mindat at www.mindat.org/loc-4448.html indicates that the Memphis mine is within a patented mining claim, and this may be what shows up as the private land on the BLM Map Viewer.

Patented mining claims are claims for which the Federal Government has passed its title to the claimant, making it private land. These are common in many mining districts on BLM and U.S. Forest Service land, and the boundaries are often not marked in the field. The Homestake mine area is within BLM land.

Preparation and Planning Foster Great Adventure

As mentioned earlier, the boundaries are not marked in the field and it is almost impossible to tell where the private land begins. We did not come across any posted ground, active or inactive claim markers, or other restrictions to visiting or mineral collecting. If you visit the area, you can use the BLM mapping link listed earlier to better determine boundaries in the field. And if you decide to stay on the BLM ground, you will still be able to find garnet, calcite, and malachite that has rolled down-slope from the main part of the mine workings.

The best way to access this site is from U.S. Route 70. Take U.S. Route 70 east from Interstate 10, and proceed about 11.3 miles to the intersection with County Road D087. Proceed approximately 0.3 miles north, and then turn right into a rough, unpaved access road to the mine area, and park at the coordinates. If you do not have a 4WD vehicle, I suggest parking on the north side of County Road D087 at a small turnout on the north side of the road

This site is a great place to see skarn minerals like garnet and marble, and the malachite is a nice bonus. If you are in the El Paso-Las Cruces area, it is an easy morning or afternoon trip. Keep an eye out for rattlesnakes and loose rocks. While we did not encounter any issues with visiting the Memphis mine area, be aware that access and land status are always subject to change.

The post North Organ Mountains first appeared on Rock & Gem Magazine.

The iron oxide mineral hematite has an amazing history that began maybe 100,000 years ago, even before ancient cave peoples used its vivid reddish color to render drawings of the animals on cave walls. When crushed to a powder, normally black hematite exhibits a lovely red color. In fact, we use hematite’s red powder streak to identify it.

It seems odd that a normally black mineral has a name based on the Greek word haimatites, which means “blood-like.” But when streaked on a piece of unglazed tile, a reddish streak illustrates the origin of the name. More obvious are the specimens of hematite with a curving ball-like surface, decidedly reddish surface color, and shaped like a human kidney. English miners even took to calling it kidney ore.

Hematite’s Early Importance

Ancient cave artists would crush hematite into a red powder and use a straw-like tube to blow it into the porous rock to create artistic images. This same powdered hematite was also smeared on the face and body as “paint” for war and decoration.

Hematite (Fe2O3) is the most common and most important of the several iron oxides. It forms lovely shiny black hexagonal crystals that can be clustered like the petals of a flower. It can also form velvety needle coatings and long curving splintery shapes. In addition, when included with other minerals, hematite’s lovely red color is even more apparent.

When one iron and one oxygen join iron oxide’s composition we call it magnetite (Fe3O4), which develops in the isometric or cubic system. Hematite is hexagonal. Combined with the OH radical, it forms goethite, hydrous iron oxide, and when hematite forms a pseudomorph after magnetite, we call it martite.

Hematite with its different crystal forms in the hexagonal system is deserving of serious collecting. It is not unusual for a collector to choose one species like quartz, calcite, or smithsonite and specialize in that one species. Hematite as a single collectible mineral is fun because of its many variations of crystal forms and worldwide sources.

The most sought-after form of hematite is sharp, lustrous tabular crystals that develop as a radiating flower-like crystal rosette several inches across. It’s not uncommon for these species to command high prices, as the rosettes are undoubtedly the most popular hematite crystal specimens. However, hematite can also form as tiny micaceous crystals that cover a matrix that is called specularite.

Taking On Various Forms

Hematite can be platy, thin, micaceous, massive, mammillary, stalactitic, scalenohedral, reniform, botryoidal, splintery, oolitic, and even present as large sharp hexagon crystals.
Though hematite is made of iron and oxygen, it is not magnetic when pure. But it can fool you because it can contain a little magnetite, which, as discussed earlier, is the magnetic form of iron oxide. With this, testing hematite with a magnet can give misleading results.

Another interesting thing about hematite is the variety of associated names. Hematite locked in greenish silica as visible red spots are often called bloodstone. When lovely tabular crystals arrange themselves in a radiating pattern that looks organic, we refer to it as iron rose.

Botryoidal and reniform hematite will often have a dull, reddish color on its surface, which led miners to call it kidney ore. Furthermore, hematite has actually been used as a gemstone in spite of a hardness that ranges only 5 to 6 on the Mohs scale. When very compact, hematite in solid masses has been carved to form pendant stones and cameos that take a fairly high polish. They can not take too much contact but can be used as an alternative to jet, the hardened gem form of anthracite coal.

Hematite has been our most important source of iron for the past centuries, but to King Tut, iron was a virtual unknown. The only iron at that time had come from meteorites as evidenced by a meteoric dagger found in the king’s tomb.

Role In Early Civilization

Gradually peoples of the Near East and China moved from the Copper

Age to the Bronze Age, which ruled the world for centuries. Then the Hittites, an advanced people of the Near East, emerged in the 18th century B.C. as a dominant civilization because they had developed a metal harder than bronze: iron. They discovered how to produce iron weapons from iron oxide hematite, and the all-important Age of Iron began.

Fortunately, we have found huge deposits of hematite all over the world. Countries including Brazil, Africa, Australia, Russia, and within the U.S. – including the Midwest and Alabama – specifically have vast deposits of iron oxide. It’s also not limited to our planet alone. Mars is called the Red Planet because of the proven presence of its iron oxide surface derived from hematite.

America’s Upper Midwest is a superb example of a vast iron oxide deposit that stretches over a couple of states and has been mined constantly for well over 100 years. This sedimentary deposit contains miles and miles of banded hematite and related iron compounds in layer after layer that is hundreds of feet thick. It certainly did not form from the welling up of hydrothermal intrusion of complex iron compounds as so many metal deposits have. Granted, the earth’s core is mostly iron, but the vast iron oxide deposits in the earth’s crust had another origin: an organic origin called cyanobacteria living in an early iron rich ocean.

An article I wrote that appeared in the October 2017 issue of Rock & Gem, “Oxygen and Our Mineral World,” told the story of cyanobacteria living in the early warm shallow seas more than four billion years ago. At that time the world’s atmosphere was made up of methane, ammonia, helium, sulfur, carbon dioxide, and other gases but very little oxygen.

Cyanobacteria is a simple-celled, organic form that evolved in the warm, shallow seas billions of years ago. It was the first organism to develop the ability to absorb carbon dioxide from the atmosphere through what is known as the process of photosynthesis. This produced oxygen.

Evolution of Hematite Deposits

But how did that result in the huge hematite iron deposits we mine today? Everyone knows that iron and oxygen in a moist environment form rust (iron oxide). It so happens that those same warm ocean waters were rich in iron. As cyanobacteria produced quantities of oxygen, an instant marriage between iron in the ocean waters and oxygen formed vast quantities of hematite, which settled to the ocean floor, millennia after millennia to create the rich iron deposits later used to initiate the Iron Age.

But Mother Nature was not finished. She gave us the means to move into the Iron Age by supplying the necessary ingredients to make steel. In those early millennia, the North American continent was nearly covered by warm, shallow seas and the Midwest region was blessed with vast deposits of iron oxide. Those same oceans also left behind thick layers of limestone, which were not too far away from vast forests that developed in a warm, moist climate. When these forests died, they became thick layers of rotting and compressed vegetation that eventually formed huge deposits of coal.

Mother Nature’s next stroke was to inject hydrothermal solutions rich in minerals including fluorite into the limestone within the central United States. This resulted in hematite, coal, limestone, and fluorite being present in the general area of the Midwest. This helped set the stage for the growth of America’s Age of Steel.

However, one additional thing was needed: a way to bring all these things together. Enter the glaciers! Nature helped when it added huge lakes and great rivers as inexpensive avenues to bring these natural ingredients together, making the Midwest one of the most prolific steel-making regions in the world. It also gave way to fine hematite, fluorite, and limestone quarry collecting sites.

Within the Mesabi range of Minnesota, we find fascinating hematite in long, slender, curving splinters that can split into dagger-like pieces. Few exceptional crystallized hematite specimens have come from the mines of the Mesabi Range. But superb fluorite, calcite, pyrite, celestine, and a host of other species have.

European Connection

The mountains of Southern Europe, especially the rugged Swiss Alps, are world-known for superb hematite specimens. Swiss mineral collectors known as stralters work the rugged hills for brilliant, bright black rosettes of hematite. They range in size from under an inch to several inches across, often with bright red rutile crystals sprinkled on shiny black crystal faces. Plus, just a few decades ago, the North Polar region of Russia began to yield superb hematite rosettes very much like the Swiss specimens, along with axinite and gwindel quartz twins.

The huge iron ore deposits of Brazil are also well-known to collectors who prize the superb tabular hematite crystals from Brumado, Novo Horizonte, Itabiria, Con Genar de Campo, and Jaguarcu. Bright, lustrous platy crystals sometimes exceeding 5” across are found here. Some crystals are pyramidal, scalenohedral, or rhombohedral.

In another part of the world, the great iron and copper mines of Cumberland, now Cumbria, England, certainly met the needs of the British Industrial Revolution. Lovely, tiny hematite blades in tight clusters on the matrix are common in this part of the world. They are often associated with quartz, sometimes with bright red iron oxide inclusions in the quartz crystals. Just as well-known are the large botryoidal masses of hematite to many inches across and pounds in weight. These are actually composed of spherules of hematite needles, which form radiating knobs that interfere with each other to form the undulating smooth surface of mammillary specimens. Some of these large pieces are covered with tiny, bright specularite hematite crystal blades. Most of these massive hematites are a lustrous black, while still others present as a reddish color to form kidney ore.

Collectors who are in love with the superb rhodochrosite specimens from the Black Rock manganese area of South Africa also enjoy fine prismatic and pyramidal hematite crystals from the Wessels mine, Hotazel. They are lustrous and sharp in well-formed crystals. Farther north is the hematite deposits of Mador Pror, Morocco, where fine bladed crystals are relative newcomers in the mineral market.

One of the great classic hematite sources is Elba, Italy, where Napoleon reportedly enjoyed leisure time. The hematite crystals from this region are hexagonal with slightly curving prism faces. Appearing in interlocking clusters, they sometimes were found penetrating bright pyritohedron pyrite crystals that developed simultaneously with the hematite. The pyrite crystals often exceed several inches across, with hematite crystals in tight interlocking crystals. Today the hematite and pyrite specimens from the Island of Elba, Italy, are considered classics.

Surely, given its many crystal forms, multiple sources, and the impact it has had on civilization, every collector should make hematite a very worthy and often very showy addition to a collection. Imagine the excitement if they ever find hematite crystals on Mars.

The post Hematite first appeared on Rock & Gem Magazine.

Deep in the Cascade Mountains of Washington state and up the Middle Fork Snoqualmie River reside the richest crystallized mineral deposits in the state. This world-class locality has provided collectors with unique specimens of quartz, amethyst, pyrite, and other accessory minerals for decades.

While there are many mineral claims up and down the valley, I had the opportunity to catch up with J.T. Hilton to visit and learn about his Hemlock Ridge claims. Not only that, but I was able to track down previous claim owners to learn about their experiences and see amazing old-stock specimens.

Hemlock Ridge Claims

This group of claims is rich in history and produced unique specimens, found nowhere else. We discussed the importance of keeping their claims active, and I even got to visit the Hemlock Claims to have a chance to find some specimens. The claims that are covered in this article reside in the Snoqualmie Batholith of the Snoqualmie-Mount Baker National Forest. This geologic formation has a long history. It all began between 28 mya and 22 mya, during the late Oligocene to early Miocene, when the old Cascade Volcanic Arc was uplifted. Natural erosion over thousands of years exposed plutonic rocks, which happened to be intruded by various rock types.

The rock type we are concerned with is intrusive breccia. It occurs when volatiles force their way to the top of an intrusion as it cools. The force causes the surrounding rock to crack. Later on, hydrothermal fluids packed with minerals make their way into these cracks, depositing their mineral load, which will later form crystals such as quartz and various sulfides.

The Hemlock Ridge claims are in the same neck of woods as the world-famous Spruce Ridge and Green Ridge claims. While Hemlock may not be as well known, it is still equally important when one considers its unique mineral combinations, which are not found anywhere else in this mountainous area. The Hemlock group consists of the Puffball, Condor, Shangri-La and Hemlock claims. Each one is unique in its own right.

Understanding the Hemlock Group

Puffball is the easiest to access, making it easier to haul up drills, blasting equipment, and hand tools. This claim may be the most unique claim; there you can find multiple mineral combinations consisting of quartz, dog-tooth calcite, pyrite, molybdenite, ankerite, siderite, and many other minerals. Puffball is the most actively worked. J.T. commonly brings along friends to help him with the hard work that is involved in removing specimens.

The Condor claim is known for its mineral combination of quartz included with bright, long, green actinolite crystal sprays. This claim is owned by three men: J.T., Ed Moslee, and Sal Noeldner. This locality is harder to reach, with a longer hike involved. However, it is always worth the trip because of its unique mineral combinations. You will likely never see quartz included with actinolite from other localities.

The Shangri-La claim is harder to get to. However, this claim is the most mineralized and is worth the hike because of the sheer abundance of quartz crystals—they lie all over in the tailings chute. The breccia is very decomposed, which makes rocks easier to move. With a large steel bar, you can easily begin plowing through the breccia, exposing quartz vugs.

Elevation Works for Early Access

Finally, the Hemlock claim rests high above the other claims, connecting Condor and Shangri-La. There is not as much activity up here because of the steepness of the claim. It is a hard-to-reach locality and there is not as much mineralization here. However, it still belongs to the Hemlock Ridge group.

All of these claims can be accessed a bit earlier in the year than some of the

surrounding active claims for a number of reasons. One reason is its elevation, which is a bit lower than some surrounding areas. Not only that, they can also be worked earlier in the year because they do not reside in a sensitive wildlife habitat. Other nearby claims have to hold off from blasting a while longer due to habitat, but since the Hemlock claims do not impose on these sensitive areas, miners can commence with blasting a month or so earlier.

J.T. has held a stake in these claims for over seven years. He has been artisan hardrock mining for over 13 years and is proficient in removing specimens in pristine condition. He is also responsible for the staking of the Puffball, Hemlock and Shangri-La claims, which he owns. He is highly motivated, often bringing everyone together to make things happen.

Five Decades of Claims

The Hemlock claims have been around for about 50 years, being worked by different groups of folks throughout the years. For one reason or another, older miners move on to other projects or sell their share of the claim, allowing new and inspired blood to take over. When J.T. and his business partners took over, these claims were not active and were receding back to their natural state. Now they are being revived, and wonderful mineral specimens are continuing to be extracted for enthusiast to enjoy.

Recently, I had taken some of my quartz crystals to a friend, Bill Mcknight, to have them processed using metal deposition, which turns them into aqua aura quartz. In conversing, I was surprised to learn that Bill, in collaboration with Bob Jackson of Spruce Ridge, used to own and work the Condor claim back in the early 1980s. Back then, this claim was called Pegasus, not Condor.

We were able to talk about Bill and Bob’s experience there, and I even got to see some of the finest material to have been mined from there. Bill’s actinolite-included quartz is spectacular. He had large, doubly terminated quartz with green actinolite sprays shooting through it. In his display case, there was also a large plate of long, slender quartz crystals; every point had phantoms and actinolite inclusions. These specimens truly are one-of-a-kind and can only be found at Condor.

On-Site at Hemlock Ridge

Bill was excited to hear of our adventures up there and passed on some of his knowledge of the claim to help these guys in their future endeavors. Toward the end of my visit with Bill, he pulled out his old photo collection of his team of guys working up there. This was a real treat to see.

Later that afternoon, after visiting with Bill, I met up with J.T. to talk more about the Hemlock claims. He expressed to me the importance of keeping these claims active and alive. In the past, these claims have been worked to varying degrees. Some periods of time have been very active and some periods of time have seen no activity, almost as though the claims had been forgotten about. Regulations, rules, and ideas of what to do with the land are always changing. Currently, the claims are on public Forest Service lands, but there is the potential that the land could be turned into wilderness land.

If that were to happen, it could affect the status of the claims. That is why it is so important to keep the claims active; as long as this happens, the hope is that the Forest Service will recognize their importance and allow the claims to continue to be worked. If the claims were not active and the Forest Service land got turned into a wilderness area, the ability to reclaim would be gone.

Another important reason to continue working hard is the unique mineral combinations that occur here. They represent the area’s mineral wealth and allow mineral collectors to see the complete picture of what can be found here. Every claim up the Middle Fork Snoqualmie River provides something unique, whether it is amethyst or large pyrite crystals. Without the Hemlock claims, that picture would not be complete, for they provide minerals that are not found at the other claims.

Trading Stories In the Field

Later that night, J.T. and I and a few others set up at the base camp and prepared to make the hike up to the Shangri-La claim the following day. Everyone else had a fire, made dinner, and traded stories about past dig adventures. My girlfriend, Brittney, and I had reservations at the Goldmeyer Hot Springs, which coincidently is in very close proximity to the claims. It is a real treat to be able to hit the hot springs before or after a day of mineral collecting.

The next morning, we all met back up and stoked the fire to share a breakfast before heading up to the claim. To begin our hike up to Shangri-la, we had to cross a fast-flowing river. Luckily for us, there was a zip line. We got our harnesses on then took turns dashing across safely to the other side. The hike up through a mix of young- and old-growth cedar and fir trees took about an hour. It was a sight to see those old-growth trees towering above our heads.

At the end of our hike, we suddenly broke out of the trees and found ourselves at the base of a very steep rock chute. Instantly, we noticed quartz crystals all over a rock chute that steeply cuts through middle of the claim. This was a good sign. We hadn’t made it to the main working area, but we were already finding quartz points littering the ground.

The Shangri-la claim consists of 20 acres and roughly encompasses the entire rock chute, as well as the rock wall exposures surrounding the chute. Some of us focused on collecting crystal points in the chute, while others went to the walls on either side of the chute in hopes of finding a fresh vug to collect from.

Joining the Climb

I had brought my rope and climbing gear, as well as a big steel bar to help

me move really big rocks. I climbed as high as I could and tied myself off for safety. Then I rappelled down over a vertical wall to a spot I felt would be productive. As I hung high above the ground, I used the leverage of my steel bar to pluck off large boulders. I kept my eyes open to spot exposed vugs, and to my luck I found a fresh vug right away. I was able to pull out multiple free-floating plates of quartz crystals. Toward the end of the day, we all reconvened to share our finds of the day and to talk about our time collecting. We all did well and were thankful for the opportunity to be out collecting fine mineral specimens in the beautiful Snoqualmie National Forest.

I was curious what the guys do with all the quartz and other mineral specimens they find. Some of the finer mineral specimens remain in their personal collections, but most of them undergo a basic acid-bath cleaning and are prepared for sale and trade. You may run into, J.T., Ed and Sal at a number of mineral shows around the state. The best place to meet these guys and see their collections is at the Seattle Mineral Market, which goes on in May. They also display some of their collection online, via social media such as Facebook and Instagram.

J.T. he revealed his plans for the future of the Hemlock claims: working hard to keep the claims active and productive. His team will be up there blasting and extracting as much as possible. J.T. shared that they would like to develop a mill site down near the base camp so they can have an area for processing minerals more efficiently and make it more comfortable for sleeping overnights. Other than that, they strive to get the word out there about the Hemlock claims and the treasures that are coming out of the ground.

Washington is held in high regard when it comes to its fine quartz specimens. Such claims as Spruce and Green Ridge have already placed the region on the map, and have shown the world what we have out here. J.T., Ed and Sal hope to continue in this tradition and share with everyone the fine specimens they are finding that can only be found in one location: Hemlock Ridge.

The post The Hemlock Claims: Sources Rich in History and Unique Specimens first appeared on Rock & Gem Magazine.

One of the oldest and best preserved human mummies ever found is that of Ötzi, a man who lived some 5,300 years ago near the present border of Austria and Italy. His remains, preserved in an alpine glacier high in the Ötztal Alps, were found 1991. That Ötzi lived during the transition between the late Stone Age and the dawning Copper Age is evident from his possessions: a flint knife and a copper axe. Also among his possession were pieces of flint and pyrite, the key materials of early percussion fire making.

Foundation of Fire

Anthropologists believe humans first created artificial fire between 250,000 and 700,000 years ago using simple drills in which wood-on-wood friction generated ignition heat. Much later, they learned to make fire by striking certain mineral materi­als with hard objects.

The first mineral-sparking material was pyrite, or iron disulfide. The striking materi­al was flint, a form of microcrystalline quartz. Harder than pyrite, flint could be easily shaped into a striking edge. When flint strikes pyrite, part of the pyrite surface shatters and emits a shower of sparks, which can ignite dry tinder.

It is uncertain when percussion fire making with pyrite began, but it was common in many cultures worldwide long before the time of Ötzi. It was quickly replaced during the early Iron Age when flint and steel became the preferred materials. Fire making “kits” of flint and variously shaped steel strikers were still used by a few isolated cultures in the late 1800s.
Pyrite survived as a sparking material only into the 16th century, notably in wheel lock firearms, in which a mechanical arm securing a piece of pyrite was placed against a serrated steel wheel. When the trigger was depressed, the spring-driven wheel rotated rapidly, abrading the pyrite and delivering a shower of sparks to ignite the powder charge.

Flintlocks Change Firing Approach

A big advance in weaponry came in 1570 with the invention of the flintlock firing mechanism, which employed shaped flints mounted on metal arms. Depressing the trigger moved the arm forward, striking the flint against an iron plate to produce sparks, which ignited the powder. During the 1700s, the manufacture of precisely shaped “gunflints” was an important industry in England and France. Both countries exported millions of gunflints each year around the world.

The introduction of modern percussion firing caps made gunflints obsolete in the 1830s. At the same time, the appearance of the friction-chemical match negated the need for other types of flint-steel-percussion fire-making devices. By then, chemists had finally answered the centuries-old question of why pyrite and steel emitted sparks when struck with harder objects. The explanation was instantaneous chemical oxidation.

Pyrite’s Role in the Firing Process

Pyrite is unstable and undergoes slow oxidation, combining with water and atmospheric

oxygen to break down into ions of iron and sulfur, which ultimately recombine into sulfuric acid and various iron hydroxides. This slow, natural process emits much heat—enough, in fact, to warm the walls of pyrite-rich, underground mines.

In percussion fire making, hard, sharp flint shatters the pyrite surface into microscopic particles, breaking its covalent bonds and releasing heat. Now exposed to atmospheric oxygen, these already hot pyrite particles instantaneously oxidize and release even more heat. Because this heat is released too quickly to dissipate, it forms a shower of visible sparks.

A similar process occurs in flint-steel percussion. Because pure iron will not spark, fire making actually requires harder, less brittle carbon-steels. When struck with flint, the steel’s metallic bonds part, fragmenting the steel and releasing heat. These tiny particles of hot steel then contact atmospheric oxygen and undergo complete, instantaneous oxidation, releasing additional heat in the form of visible sparks.

Ötzi, as he made his way across the Ötztal Alps some 5,300 years ago, had no knowledge of chemical oxidation, but he was nevertheless quite adept at making fire with dry tinder, flint and pyrite.

The post Examining Pyrite, Iron and Flint: The Fire Makers first appeared on Rock & Gem Magazine.