Mineral on EARTH Magazine

Lab-grown magnesite a boon for carbon sequestration?

Thu, 17 Jan 2019 13:29:51 -0500

Left undisturbed, carbonate minerals can naturally lock up carbon in a stable form for millions of years or longer. Triggering the formation of carbonate minerals is thus a promising means of removing and sequestering carbon dioxide from the atmosphere. In recent research, scientists uncovered new details about how one of Earth’s most stable, albeit slow-to-form, carbonates — magnesite — grows in nature and have found a way to accelerate its formation in the lab at room temperature. The results could aid in developing efficient carbon sequestration technologies.

"Critical Minerals" list snubs copper, sparks discussion of criticality

Thu, 08 Nov 2018 13:03:34 -0500

Many people think copper ought to be on the U.S. list of critical minerals, but it was left off in part because the U.S. has a fairly robust domestic supply from mines such as Bingham Canyon Copper Mine in Utah. Credit: Doc Searls, CC BY 2.0.

In 2017, the United States relied on imports for more than half the needed supply of 50 mineral commodities that are critical in manufacturing. Some of the commodities come from just a few major suppliers — especially China and Canada — or are produced in tiny quantities in just a few places. Others come from conflict zones. Some are produced only as byproducts of processing ores of major metals, such as copper and zinc. Such complex international supply chains are at risk of being disrupted by a variety of problems, from trade wars and market volatility to natural disasters and terrorism.

Data-driven discovery reveals Earth's missing minerals

Tue, 01 May 2018 10:31:26 -0400

Missing Minerals graphic. Credit: Image credit: K. Cantner.

Fueled by advances in computing power and analytical methods, researchers in a growing number of scientific fields have taken to mining large datasets to reveal big-picture insights. By tallying the words that appear in a sampling of a book’s pages, for example, lexicologists — interested in tracking trends over time in language or literature — can mathematically predict the total number of distinct words in the book or, say, the number of different words containing a certain letter or certain combinations of letters.

Isotopes suggest ancient turquoise mine was prolific

Wed, 10 Jan 2018 10:37:55 -0500

This turquoise mosaic piece from a precolonial site in Arizona has isotope ratios consistent with geologic samples from Canyon Creek. Credit: Saul Hedquist.

Few minerals are more iconic in the Desert Southwest than turquoise. The blue-green gemstone, which offers a stark contrast to the dusty red southwestern deserts, has been coveted for thousands of years by indigenous peoples, conquering Spaniards and now by a growing market around the world. Despite its past and present cultural significance, especially among indigenous populations, little is known about the early history of turquoise mining. Researchers have now uncovered previously unknown details about a historic turquoise mining site in Arizona that suggest it was more prolific than once thought.

In feats of tectonic strength, grain size matters

Thu, 14 Dec 2017 15:43:47 -0500

Olivine is the dominant mineral in Earth's lithosphere, and thus largely controls the strength of tectonic plates. Credit: Evan Krape/University of Delaware.

Plate tectonics involves some of the most powerful forces on Earth, but the lithosphere, of which the plates are made, is not infinitely strong: Weaknesses in the lithosphere allow it to break apart and form plate boundaries. Determining the strength of tectonic plates based on field observations has proved tricky, however, due to the sheer scale of plates, while experiments and calculations in the lab on olivine — the main mineral that makes up the lithosphere — have depicted plates as misleadingly strong. In a new lab-based study, researchers have taken a novel approach to testing olivine’s strength, and the results fit existing models of plate tectonics better than previous efforts.

Minerals deformed by meteorites reveal age of impact

Tue, 19 Sep 2017 11:30:41 -0400

The Willamette Meteorite on display at the American Museum of Natural History in New York City. Credit: Dante Alighieri, CC BY-SA 3.0.

Researchers have discovered a new way to determine when a meteorite hit Earth, a technique that could not only help scientists date ancient meteorite strikes but also determine when planetary crusts first formed.

Ups and downs of potassium feldspar may play role in clouds and climate

Wed, 17 May 2017 10:09:58 -0400

Potassium feldspar is one of the main mineral components of Yosemite's famous granite, giving it a pinkish hue. Credit: Mary Caperton Morton.

For water vapor in the atmosphere to transform into icy, cloud-forming droplets, it needs a seed around which to condense, such as aerosols, sea salt or bacteria. One of the most effective seeds is mineral dust, in particular potassium feldspar, one of the main ingredients in granite. New research tracking fluxes of potassium feldspar in the atmosphere through geologic time is shedding light on the long-term importance of the mineral in cloud formation and climate feedback cycles.

Investigating erionite, asbestos' more carcinogenic cousin

Wed, 19 Apr 2017 14:19:15 -0400

Blocks of volcanic tuff quarried from this mine in Turkey contain carcinogenic erionite. Credit: F. Mighali (Kaltun Italia S.r.l.).

Asbestos is notorious for causing lung cancer and other respiratory diseases, but it’s not the only type of fibrous mineral that affects human health. In the mid-1970s, erionite was linked to the unprecedented high mortality rate from mesothelioma in villages in central Turkey where volcanic tuff had been used as a building material for centuries. Like asbestos, erionite can occur as long thin fibers that, when inhaled, can persist in lung tissue for decades. New research looking at associations of iron with erionite is helping pathologists better understand why embedded erionite fibers sometimes lead to lung cancer.

Isotopes could reveal ancient American turquoise trade

Mon, 02 Nov 2015 11:24:21 -0500

Mines in the Halloran Hills of California's San Bernardino County were one location where researchers collected samples of turquoise to study the mineral's lead and strontium isotopic compositions. Credit: Alyson Thibodeau.

For centuries before the arrival of Europeans, turquoise was prized among pre-Hispanic cultures of North America. Caches of the distinctive, creamy-blue-green mineral have been unearthed in crypts and other ritually significant structures in what are now the southwestern United States and northern Mexico. Farther south, in Mesoamerica, archaeologists have found elaborate mosaic masks and ornamentation made of turquoise pieces. Despite multiple anthropological and historical hints, identifying where the turquoise used by different civilizations came from has proven difficult. But in a recent study, scientists have described a geochemical fingerprinting technique that may help parse the geographic origins of turquoise specimens and illuminate trade routes in ancient America.

Stalled slabs sometimes stopped by mineral strengthening

Thu, 16 Jul 2015 13:23:14 -0400

In some subduction zones, the downgoing slabs get stuck at depths of about 1,000 kilometers, held up by some unseen barrier that might be related to high-pressure-induced strengthening of minerals in the rocks surrounding the subducting slabs. Credit: K. Cantner, AGI.

Subduction of tectonic plates into the mantle functions as an eons-long recycling system for Earth’s crust and lithosphere. But in some subduction zones, the downgoing slabs seem to get stuck at depths of about 1,000 kilometers, held up by some unseen barrier on their journey deeper into the lower mantle. Now, scientists propose that this barrier might be related to high-pressure-induced strengthening of minerals in the rocks surrounding subducting slabs at these depths.

Benchmarks: July 22,1960: Mineral discovery ends Meteor Crater debate

Mon, 08 Jun 2015 11:03:24 -0400

Meteor Crater near Flagstaff, Ariz. Credit: NASA Earth Observatory.

In 1923, Daniel Moreau Barringer stood on the edge of a vast bowl-shaped depression in the Arizona desert, watching a drill rig bore into the floor of the crater. Barringer had spent more than two decades exploring the massive hole, which lies on the Colorado Plateau 65 kilometers east of Flagstaff, Ariz. And although he had sunk dozens of drill holes, collected scores of samples, and carefully mapped the piles of talus that draped its concave walls, Barringer still hadn’t found what he was looking for, and he was getting nervous.

Earth's most abundant mineral finally gets a name

Tue, 12 May 2015 13:55:52 -0400

The most abundant mineral on Earth, bridgmanite, has been named after Percy W. Bridgman, recipient of the 1946 Nobel Prize in Physics. Credit: Public domain.

Bridgmanite, earth's most abundant mineral. Credit: Chi Ma.

An elusive, high-density form of magnesium iron silicate, long known colloquially as “silicate perovskite,” now officially bears the name “bridgmanite,” after the father of high-pressure experiments, Nobel laureate Percy W. Bridgman.

Down to Earth With: Mineralogist George W. Robinson

Fri, 30 Jan 2015 13:14:44 -0500

George Robinson has dedicated his life to finding, curating and sharing exceptional mineral specimens. Credit: John Jaszczak.

Many geologists understand the joyous feeling of coming across a beautiful rock in the field; George W. Robinson, who began collecting minerals at age 9, has had a lifetime full of such moments. After delving deeper into his early avocation as a teenager, he received his doctorate in mineralogy from Queen’s University in Kingston, Ontario, in 1979. He has worked as a high school earth science teacher, field collector, mineral dealer, museum curator and professor — all occupations that shared a common focus: a love of minerals.

Asbestos found in Nevada and Arizona: Roadblock and potential health hazard?

Thu, 29 Jan 2015 09:04:03 -0500

Naturally occurring asbestos has been found in and around Boulder City and Henderson in southern Nevada, including in many desert areas popular with mountain bikers, hikers, horseback riders and recreational vehicle users. Boulder City lies about 30 kilometers southeast of Las Vegas and west of Lake Mead, seen here. Credit: ©Prayitno, CC BY 2.0.

In 2011, Brenda Buck, a medical geologist at the University of Nevada, Las Vegas (UNLV), was studying the human health effects of mineral dusts at Nellis Dunes — a 40-square-kilometer area northeast of Las Vegas that is popular with off-road enthusiasts, 300,000 of whom visit the dunes each year.

Protecting the mineral treasures of Antarctica's Larsemann Hills

Mon, 29 Dec 2014 12:38:44 -0500

It was late November 2003 and not quite summer in Antarctica. As the Squirrel helicopter lifted off after delivering its last load, we set about putting up our two tents and making camp on Stornes Peninsula. The peninsula, which would serve as our home and base for fieldwork for the next two months, is part of the Larsemann Hills, a 40-square-kilometer region of rocky islands and promontories on the eastern shore of Prydz Bay, some 120 kilometers southwest of one of Australia’s Antarctic bases, Davis Station. Our only contacts with the outside world were twice-daily radio calls and an occasional helicopter flight to refurbish our larder and take out our samples. No telephone, no Internet.

Mineral Resource of the Month: Arsenic

Mon, 04 Aug 2014 10:02:57 -0400

The most common arsenic-containing minerals are arsenopyrite, realgar and orpiment (shown here). ©Elke Wetzig, CC BY-SA 3.0.

George Bedinger, mineral commodity specialist for the U.S. Geological Survey, prepared the following information on arsenic.

Rescuing geologic maps during a coup

Thu, 15 Aug 2013 08:44:17 -0400

courtesy of John F. (Jack) Shroder Jr.

The author shows a map of the geomorphology of northern Afghanistan to Afghan President Hamid Karzai and others at the University of Nebraska in Omaha in 2005. The author created the map in the summer of 1978, between the communist coup in May and his deportation from Kabul that fall. The map was an early “trafficability” type (including active sand dunes and shifting rivers, as well as active tectonics [rising anticlines and piercement salt domes]). Right after the coup, he says, he knew his days were numbered so he loaded his truck with food and headed out of Kabul in the north to field-check this map. When he ran out of supplies, he returned to Kabul, where Afghan communist officials found him and pressured him to turn over all his maps. However, his cook, Abdul Waheed, surreptitiously took the maps to the U.S. embassy — on his bicycle — and they were shipped back to the U.S. in a diplomatic pouch. This is one of the few maps to make it out. The author was house arrested after this for three months and was finally deported on a few hours’ notice, driven to the airport and put on a Lufthansa jet to Germany.

Building resource corridors in Afghanistan: A solution to an interminable war?

Wed, 14 Aug 2013 12:24:30 -0400

When possible, USGS scientists work together with Afghan geologists to create new resource maps. U.S. Geological Survey

USGS researchers mapped mineral resources on remote sensing missions in Afghanistan. U.S. Geological Survey

Areas near Kabul are rich in copper. U.S. Geological Survey

Afghanistan has been ravaged by decades-long conflicts that have left it economically depressed, but the country also holds a potentially huge natural resource base. Some estimates have put the value of the resources — copper, gold, coal, oil, gas, industrial minerals, rare earth minerals and more — between $1 trillion and $3 trillion. If those resources can be extracted and sold legitimately, they could help the country recover from decades of violence and allow its population to reap the rewards of their considerable natural assets. The sizable mineral and energy resources awaiting exploitation bring the possibility of thousands of new jobs and great wealth enhancement in a chronically wage-starved country.

Dangerous dust: Erionite - an asbestos-like mineral causing a cancer epidemic in Turkey - is found in at least 13 states

Mon, 30 Jan 2012 11:52:52 -0500

A gravel road north of North Killdeer Mountain, one of the sites where erionite was found in road gravel in 2006. Ed Murphy, North Dakota State Geologist

An epidemic of mesothelioma is responsible for half the deaths in some villages in the Cappadocia region of Turkey, where villagers have built homes of, and in, the erionite-bearing stone. Michele Carbone, University of Hawaii Cancer Center

As North Dakota’s state geologist, Ed Murphy has spent a fair amount of time mapping the geology of the Killdeer Mountains in the western part of the state, hiking up and down buttes of the White River Group and the Arikaree Formation. In the 1980s, he and colleagues mapped large deposits of rocks bearing erionite — a zeolite mineral formed when volcanic ash is altered by water — that may have had some commercial use. No use was ever found for the mineral itself, but for roughly 30 years, several gravel-mining operations have been excavating the chalky, grey-brown rock from these erionite-bearing formations. It was then crushed and spread on nearly 500 kilometers of roads in Dunn County, as well as on playgrounds, baseball fields, parking lots and even flower beds.

Afghanistan's mineral resources laid bare

Mon, 23 Jan 2012 13:54:08 -0500

Geologist Said Mirzad (left) surveyed Afghanistan's mineral resources with colleagues from the U.S. Geological Survey and the Afghanistan Geological Survey (and a military escort). Courtesy of Said Mirzad

Marines from the First Reconnaissance Battalion, C Company, stand guard as a helicopter drops to pick up civilian scientists at the Khanneshin carbonatite complex in August 2010. Tina Hager, TFBSO

Forrest Horton (left), Robert Tucker (middle), and Emily Scott come across the first sign of rare earth element mineralization in the Khanneshin carbonatite complex. Tina Hager, TFBSO

Robert Tucker (left), Alex Chairhorsky (middle), and a Marine look at a specimen of rare earth element minerals from the Khanneshin massif. Tina Hager, TFBSO

The Khanneshin carbonatite complex hosts rare earth elements. Tina Hager, TFBSO

A mineral assessment milestone confirms world-class resources

Each donning about 10 kilograms of protective gear, including helmets and Kevlar, scientists trudged up the rugged, rocky volcanic terrain of southern Afghanistan, slowing now and then to catch an extra breath of thin air. Some carried guns. Others carried rock hammers.

Afghanistan's mineral wealth

Thu, 05 Jan 2012 06:41:58 -0500

Blogging on EARTH

On Monday, a spokesman for Afghanistan's President Hamid Karzai, Waheed Omar, told reporters that the USGS survey of Afghanistan's mineral resources found they are worth about $1 trillion. And on Wednesday, USGS will host a press conference in which scientists will discuss water issues in Afghanistan.

Crystal Ball EARTH: Minerals management: The changing commodities scene

Thu, 05 Jan 2012 06:41:58 -0500

The demand for smaller, more fuel-efficient cars may be good news for producers of the lightweight metal aluminum. Megan Sever

Many people would like to forget 2008. The subprime mortgage crisis came to a head and sent the world’s financial markets into a free fall. The situation didn’t improve much in 2009 as unemployment soared and consumers held on tightly to their dwindling dollars.

Is there really a minerals crisis?

Thu, 05 Jan 2012 06:41:58 -0500

China sent the high-tech industry and markets reeling last September when it blocked exports of raw rare earth minerals to Japan. In mid-October of that year, China imposed a similar ban on rare earth exports to the United States and Europe. The sudden severing of rare earths supply was a frightening prospect: Rare earths are a hot commodity in the modern world, because they are the key ingredients in a broad range of high-tech products, from smartphones to wind turbines to hybrid cars. Although China lifted the ban on exports of rare earths to the United States and Europe by late October, the ban on exports to Japan — although unofficial — remained in place for months.

Restarting U.S. rare earth production?

Thu, 05 Jan 2012 06:41:58 -0500

Rare earth minerals experts testified in front of the House Subcommittee on Science and Technology in March. Left to right: Stephen Freiman, Freiman Consulting, representing the National Research Council's Committee on Earth Resources; Steven Ducos, GE Global Research; Karl Gschneidner Jr., Ames National Laboratory and Iowa State University; Mark Smith, CEO of Molycorp Minerals; and Terence Stewart, Law Offices of Stewart and Stewart. Courtesy of the House Committee on Science and Technology

Rare earth minerals are not actually rare, but if China has anything to say about it, they may become scarce in the near future, experts say. And that could pose real problems for the U.S.’ high-tech industries that rely on the metals, including everything from hybrid cars to renewable energy to computers and mobile phones. But in March, rare earth experts testifying before the U.S. House of Representatives said that there is a way to avoid this potential shortage: Reopen a long-idle U.S. mine.