wpengine

July 6, 2021 by wpengine

Bird Architecture on Human Infrastructure

by Patrick McShea

cliff swallow nests — Image credit: Amy Henrici

Cliff Swallows are potters. The gourd-shaped earthen vessels the birds construct, one tiny mouthful of mud at a time, provide shelter for their eggs and young. In Pennsylvania, and across much of the species’ current continent-wide breeding range, bridges provide favored nest sites for birds whose ancestors, until the early decades of the 1800’s, seem to have been restricted to nesting against low elevation cliffs in western mountain ranges.

The nests pictured above adhere to the concrete supports of a bridge crossing an arm of Lake Arthur in Butler County’s Moraine State Park. During field survey work leading up to the publication of the Second Atlas of Breeding Birds in Pennsylvania in 2012, bridges accounted for 44% of Cliff Swallow nest sites, barns for 33%, and churches, houses, other buildings, and dams for the balance. The species nests in colonies, and the number of nests in bridge-based colonies also far outnumbered those at other sites.

In Birds of Western Pennsylvania, a 1940 publication by W.E. Clyde Todd, then the museum’s Curator of Birds, nest descriptions are a highlight of the Cliff Swallow account.

“The type is retort-shaped, globular, with a neck springing from above and turned to open downward: a beautiful, symmetrical structure. The shape however is modified to suit the space – truncated or extended, as need requires; and where the nests are close-set, the chamber within, though pouch-like, is not truly symmetrical.”

“The nests are built of pellets of mud laid wet and retaining in the finished structure, each its smooth-rounded individuality. The walls speak of cunning and labor and of security, as does a wall of human masonry.”

cliff swallow feeding young in the nest — Image credit: Amy Henrici

On a recent early summer morning the Cliff Swallows’ incorporation of our culture’s indispensable highway architecture into their reproductive cycle made for easy and entertaining bird watching. There were hungry young in every chamber of an easily viewed eight-nest cluster. As parent birds returned regularly from insect-catching forays over the nearby lake, the entryways to the dark clay pouches were brightened by the bright yellow gaping beaks of the young.

cliff swallow hanging out of nest — Image credit: Amy Henrici

Appreciation of the beneficial match between people and birds was leavened by a sight at another nest cluster on an adjacent bridge support. When a swallow perched against a nest remained still through several feeding cycles of its neighbors, an inspection with binoculars revealed a tragic circumstance. The bird appeared to have become entangled in, and eventually strangled by discarded fishing line, eight inches of which dangled from the lifeless feathered body.

Patrick McShea works in the Education and Visitor Experience department of Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

Reference

Second Breeding Bird Atlas of Pennsylvania – http://www.pabirdatlas.psu.edu/

Fish and the Fourth of July?

by Patrick McShea

During the cold early months of 1778, did the outcome of the American colonies’ armed struggle for independence hinge upon a spawning run of fish up a Pennsylvania river? A 22-inch-long American shad displayed on a wall in Discovery Basecamp can serve as a focal point for consideration of this question, but many viewers will be aided by some framing background information.

In the chronology of the American Revolution, the harsh winter of 1777-1778 was notable for the British Army’s control of Philadelphia, and the encampment, some 23 miles northwest, of the opposing Continental Army, led by George Washington, at a site along the Schuylkill River known as Valley Forge.

In the more than two centuries since the United States achieved independence from Great Britain, an often repeated anecdote about the desperate conditions endured by the poorly clothed, poorly fed, and poorly sheltered soldiers at Valley Forge contends that starvation conditions were ended late in the winter by an unusually early spawning run of thousands of American shad up the Schuylkill.

American shad are an anadromous species, a term for fish that hatch in freshwater, migrate to the ocean where they spend most of their lives, and then migrate back to their natal waters to reproduce. The historic range for the species, whose Latin name, Alosa sapidissima, references its delectable flavor, encompasses western Atlantic Ocean waters bordering the east coast of Canada and the United States.

In 2002, renowned author and Princeton University professor John McPhee brought American shad to the attention of the book-reading public with the publication of The Founding Fish, a 358-page encyclopedic compilation of personal experience, firsthand reporting, historical accounts, and scientific research. (Farrar, Straus, and Giroux) The book’s title is a nod to the Valley Forge account, and in a central chapter of the same name McPhee addresses the story’s veracity by citing the research of a now retired professor of American History from Indiana University of Pennsylvania, Wayne Bodle. “When I first got in touch with Bodle, in 1998, he said that fresh shad in all likelihood were consumed by soldiers at Valley Forge in the weeks before they broke camp in June, but that the large and providently early run is a legend not supported by a single document.”

Bodle’s analysis of his research into all aspects of the Continental Army’s storied winter encampment in eastern Pennsylvania is presented in his book, The Valley Forge Winter: Civilians and Soldiers in War (The Pennsylvania University Press, 2002). Like The Founding Fish, it’s available for borrowing from Carnegie Library of Pittsburgh. If your summer reading schedule isn’t yet set, you might consider checking out either book.

Cuttlefish Pass Marshmallow Test

by Tim Pearce

The club for species that can pass the marshmallow test has recently gotten a new member: the cuttlefish. Cuttlefish are the first invertebrate known to show self-control.

The marshmallow test examines whether an individual has sufficient self-control to use delayed gratification. In the original marshmallow test, a child could have one marshmallow immediately, or if they were able to wait 15 minutes, they received two marshmallows. Some of the 3- to 5-year-old children waited and got the double treat, indicating that they could delay gratification for a larger reward. Other species such as chimpanzees, crows, parrots, and dogs have passed modified versions of the marshmallow test

We humans think we are special. We form clubs in which we initially believe we are the only member, but then other species creep into those clubs. In times past, humans thought they were the only members of the language club and the tool use club, but now we know many other species are in those clubs.

cuttlefish on dark background — Cuttlefish. Image by David Sim, from Wikimedia Commons under the Creative Commons Attribution 2.0 Generic license.

To examine whether cuttlefish could delay gratification for a better reward, researchers (Schnell et al. 2021) offered them an Asian shore crab (a less preferred food) immediately, or a grass shrimp (a more preferred food) if they were able to wait. The food was offered in two chambers with sliding doors. Before the test, cuttlefish were trained to recognize symbols on the doors that indicated if it would open immediately (a circle) or with a delay (a triangle). Most of the cuttlefish waited 50 to 130 seconds to get the more desirable grass shrimp, comparable to time delays shown by chimpanzees and crows.

Some cuttlefish appeared to move their bodies away from the immediate, less preferred reward. Similar behaviors are seen in humans and other animals (e.g., parrots close their eyes, dogs turn away) as they try to resist temptation while waiting for the better reward.

Furthermore, those cuttlefish that waited longest for their favorite foods also performed best during learning tests. Cuttlefish have good memories and can learn from past experiences.

The standard explanation for ability to use delayed gratification, is that it helps animals with long, social lives. This reasoning doesn’t apply to cuttlefish. They live just two years and are not social, so the benefits of delayed gratification to cuttlefish are less obvious. One possibility is that the evolution of self-control in cuttlefish is related to predator avoidance and camouflage; those that can stay camouflaged longer might avoid detection by predators.

Relevant joke:

What is the most affectionate fish in the ocean?

The cuttlefish!

Tim Pearce is the head of the Section of Mollusks at Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

Reference

Schnell, A.K., Boeckle, M., Rivera, M., Clayton, N.S. & Hanlon, R.T. 2021. Cuttlefish exert self-control in a delay of gratification task. Proceedings of the Royal Society B, Biological Sciences, 288 (1946): 20203161 doi.org/10.1098/rspb.2020.3161.

What Did Dinosaurs Sound Like?

A Brief Foray into Paleoacoustics in Science and Film

by Niko Borish and Caroline Lee

Did Dinosaurs Roar?

When you think about dinosaurs as living animals, what do you think of? Many people imagine them as they are depicted in the Jurassic Park films – giant reptiles, clad in scales, generating reverberating roars that shake the screen. Although this image is certainly entertaining, research in recent years points to unexpected findings that are no less interesting. Evidence suggests that dinosaur vocalizations were not likely to have sounded like roars at all! We’ll explore what’s known about the real voices of dinosaurs with a paleontological source and an interview with an expert who has made relevant discoveries. We’ll also discuss how the sounds you hear in the Jurassic Park films were created!

Paleoacoustics and Dinosaur Vocalizations

We had a chance to interview Dr. Julia Clarke, a paleontologist at the University of Texas, to learn more about paleoacoustics (the study of sound associated with fossils) in non-avian dinosaurs and their evolutionary descendants, birds. In Antarctica in the mid-1990s, Vegavis iaai, an ancient bird dating to around 66 to 68 million years ago, was excavated. Dr. Clarke analyzed the fossil, and in 2013 found evidence that Vegavis had a vocal organ specific to birds, known as a syrinx. In extant (meaning alive today) bird species, the syrinx is responsible for all the vocalizations we identify as bird songs or calls. This means that Vegavis most likely honked (not unlike a goose), owing to an asymmetrical third segment in the syrinx. When we asked why it took about two decades to find the syrinx after the fossil’s original discovery, Dr. Clarke answered that “discovery is not just one moment.” She received the fossil for study in 2008. When she was about to return it in 2012, she went over its computed tomographic (CT) scan images again and noticed something new – a tiny structure that looked like a simple bone fragment or toe bone on the surface of the rock. It turned out to be the syrinx! Clarke and her coauthors noted that we still don’t know when the syrinx evolved because non-avian dinosaur fossils lack this structure. Vegavis is related to extant bird species, and despite searching, no earlier dinosaur syrinxes have so far been found.

Carnivorous dinosaurs are often pictured as chasing prey while letting out intimidating roars. Other new discoveries made from studies of extant birds indicate that this image is a misconception. Dr. Clarke explained that instead of open-mouthed roars, scientists theorize that many dinosaurs may have produced closed-mouth vocalizations. Animals produce closed-mouth vocalizations by inflating their esophagus (the tube that connects the throat and stomach) or tracheal pouches (pouches on their windpipe) while keeping their mouth closed, producing something comparable to a low-pitched swooshing, growling, or cooing sound. These closed-mouth vocalizations differ substantially from open-mouth vocalizations like bird calls. Think of closed-mouth vocalizations as being lower and more percussive, as opposed to bird calls, which are more varied in pitch and almost melodic. Modern examples of closed-mouth vocalizations include crocodilian growls and ostrich booms. As a result, scientists reasoned that many dinosaurs did not perform open-mouth vocalizations, but could have generated closed-mouth vocalizations instead. Although birds evolved from theropods (a group of dinosaurs characterized by, among other attributes, hollow bones and a bipedal stance), theropods likely did not have the ability to make complex sounds similar to those of extant songbirds.

Perhaps sadly, the exciting, blood-curdling roars in the Jurassic Park franchise are not scientifically accurate. Current evidence supports that Tyrannosaurus rex made closed-mouth vocalizations, but in the films, the Tyrannosaurus opens its mouth every time it roars. That begs the question: who or what voiced the Tyrannosaurus and other Jurassic Park dinosaurs? The majority of the sounds used to create the Tyrannosaurus sonic palette came from recordings of elephant bellows. Also used were crocodilian growls, roars from lions and tigers (but not bears), the sound of water coming up from a whale’s blowhole, and even growls from the sound producer’s dog. Some other animals’ sounds that were used to make different dinosaurs’ vocalizations include: hawing donkeys, neighing horses, growling tortoises, whistling dolphins, howling howler monkeys, oinking pigs, barking fennec foxes, and chirping birds! Most of these sounds were edited and pitched up or down to fit their roles.

Another popular misconception initiated by the Jurassic Park franchise was the concept of the “Velociraptor resonating chamber.” In Jurassic Park III, the protagonists search for a “Velociraptor resonating chamber” that allows them to communicate with the Velociraptor pack. However, the possibility of this structure was debunked by Dr. Clarke and Dr. Matt Lamanna, a paleontologist at Carnegie Museum of Natural History. The resonating chamber does not actually exist. If such a chamber existed, it would only amplify the sound (auditory vibrations that travel through the air) made by dinosaurs, not modify its timbre (the tone quality of a sound) or pitch (a measure of how high or low a sound is), which would not allow humans to imitate Velociraptor sounds as shown in the movie. In other words, it would not work like a giant duck call. Additionally, the way that scientists perceive closed-mouth vocalizations to function disproves the whole idea of a resonating chamber to begin with. This is because the organs involved in vocalization include either esophageal or tracheal pouches but no dedicated “resonating chamber.”

What non-avian dinosaurs really sounded like is an enigma currently being uncovered by teams of researchers like that led by Dr. Clarke. All in all, while the movies are certainly helpful for getting people interested in dinosaurs and paleontology, a logical next step is to schedule a visit to Carnegie Museum of Natural History to get the real facts!

We would like to extend a gargantuan thank-you to Dr. Julia Clarke and Dr. Matt Lamanna for generously offering expertise for our blog! Their help evolved our blog to the next level, and for that we are extremely grateful.

Niko Borish and Caroline Lee are Teen Volunteers in the Education Department. Museum employees, volunteers, and interns are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

References

Analysis of fossilized Antarctic bird’s ‘voice box’ suggests dinosaurs couldn’t sing. (2016, October 12). National Science Foundation. Retrieved March 7, 2021, from https://www.nsf.gov/news/news_summ.jsp?cntn_id=189996

Clarke, J. (2016, July 16). New Research Debunks The Dinosaur’s Roar (Interview by L. Wertheimer) [Radio broadcast]. In Weekend Edition Saturday. National Public Radio. https://www.npr.org/2016/07/16/486279631/new-research-debunks-the-dinosaurs-roar

Riede, T., Eliason, C. M., Miller, E. H., Goller, F., & Clarke, J. A. (2016). Coos, booms, and hoots: The evolution of closed-mouth vocal behavior in birds. Evolution, 1734-1746. https://doi.org/10.1111/evo.12988

Taylor, D. (Host), & Nelson, A., & Clarke, J. (n.d.). Tyrannosaurus FX (No. 105) [Audio podcast episode]. In L. Battison (Producer), Twenty Thousand Hertz. Twenty Thousand Hertz. https://www.20k.org/episodes/tyrannosaurusfx

Diamonds Are the World’s Best Friend: The Important Roles Diamonds Play in Society

by Shelby Wyzykowski

In the classic 1953 movie “Gentlemen Prefer Blondes” is a memorable musical number performed by silver screen legend Marilyn Monroe. Wearing a striking pink satin gown and dripping in dazzling jewels, she is surrounded on the stage by a bevy of handsome suitors that are dressed to the nines. In this glamorous setting, she sings the praises of diamonds…how nothing in the world can compare to how it feels to possess these glittering gemstones. But off-screen, Monroe’s taste in brilliant baubles was radically different, preferring costume jewelry to the real thing. I have to admit that I agree with Marilyn. Diamonds have never held much interest for me. That is until now. After doing a little research, I’ve discovered that, besides their use in the jewelry industry, there are other ways in which diamonds are utilized in society today. In fact, there is so much more to these captivating stones than just their scintillating sparkle.

Perhaps you’ve heard the adage “one person’s trash is another person’s treasure.” Well, it just might surprise you that this saying holds true for diamonds. In the jewelry world, a diamond with perfect clarity is the much-desired ideal. But in the scientific world, a so-called “poor” specimen that is full of inclusions (imperfections), could hold a treasure trove of geologic information. Researchers are studying them to try and uncover the secrets of the deep-Earth environment. The majority of diamonds are created fairly close to the Earth’s surface, between 93 and 150 miles down. But there are some diamonds, called super-deep diamonds, that come from far down in the Earth’s mantle and are as deep as 500 to 600 miles (the mantle, which is mostly made up of solid and very hot rock, is directly below the Earth’s surface layer, or crust, and makes up more than 80 percent of our planet’s volume). These 3.5 billion-year-old gems formed at a pressure that is 240,000 times the atmospheric pressure at sea level, and this fact makes these tiny stone time capsules extremely valuable to researchers. No doubt geologists would love to travel deep under our planet’s surface like the characters in Jules Verne’s 1864 science fiction novel Journey to the Center of the Earth. Unfortunately they can’t, but these super-deep diamonds are the next best thing to journeying there themselves!

With these diamonds, scientists are uncovering clues to the origins of water on Earth. Did water come from incoming asteroids and comets, or was water an integral component at the planet’s formation? We’re still not quite sure. But diamond research has brought us closer to figuring out how much water lies deep underground. Scientists think that there may in fact be as much water present in our planet’s deep subsurface as there is found in our oceans. They have developed this idea after discovering a special water encased in the inclusions of deep diamonds. Called ICE-VII, this water ice can only be formed under tremendous deep-Earth pressure. In addition to water, geologists have found an elusive mineral in diamond inclusions. Scientists had theorized it to be an extremely common mineral that makes up to 38 percent of the Earth’s volume, but it’s been impossible to create in a lab. Now that it’s been found in nature, researchers have the proof of its existence and have named it Silicate-Perovskite (or Bridgmanite). In addition to Bridgmanite, they have discovered other trace minerals and elements that are commonly present in the Earth’s crust. This means that the materials were subducted (drawn back down into the Earth) billions of years ago by plate tectonics. Deep in the mantle, the materials were encased in a forming deep-diamond and then eventually sent back up to the surface by way of volcanic eruptions. Even more exciting than all of these discoveries is the thought of what geologists still have yet to uncover. They still hope to find carbon from primordial organic matter in these special diamonds. That matter could be a clue to the origins of life on Earth!

specimen of bridgmanite — “Earth’s most abundant mineral finally has a name” by Argonne National Laboratory is licensed under CC BY-NC-SA 2.0

In addition to their contributions to the scientific field, diamonds also have practical uses in society. In the mid-1950’s, synthetic diamonds were invented. Created in a lab, they are chemically and physically exactly the same as natural diamonds. However, these man-made gems do not possess the allure and mystery of natural diamonds, so they are not very desirable in the jewelry market. But since diamonds are the hardest known natural substance, they are ideal for industrial use. For example, they can be pulverized into a fine abrasive that can be made into a “diamond paste” and used for polishing other jewelry-grade gemstones. Small particles of diamond can also be embedded in tools like saw blades, drill bits, and grinding wheels. These diamond-coated tools are very wear-resistant and can be used for mining, deep-sea drilling, and road construction. And there are some ingenious uses for diamonds that you may find to be very surprising. Diamond windows can be made from very thin (thinner than a human hair) diamond membranes. These windows cover X-ray machines, laser openings, and vacuum chambers. A diamond can also make your music sound better. A speaker dome made out of diamonds can vibrate very rapidly because this gem is such a stiff material. So it is ideal for enhancing the performance of high-quality speakers. Diamonds can even help you keep track of time. Small mechanical devices, such as watches, have tiny bearings inside of them that make everything move (in a watch, it’s called its “movement”). A thin coating of diamond makes these parts wear-resistant and ensures accurate time-telling and lasting durability. From helping to build highways to making your timepiece tick, who knew that diamonds could be so useful in so many ways!

CM18561 is located in the Native Elements case in Hillman Hall of Minerals and Gems. Source: https://carnegiemnh.org/emu_widgets/mineralogy.html#details=ecatalogue.2019718

Yet another important role that diamonds have played in our world is how they have influenced history. The brilliantly blue, supposedly cursed Hope Diamond, for example, has not brought much luck to its owners since it was discovered over 350 years ago. It was in the possession of Marie Antoinette and Louis XVI until their untimely deaths during the French Revolution. Subsequent owners also met with unfortunate outcomes until it was donated to the Smithsonian National Museum of Natural History where it is now safely on display. Another famous diamond, the 750 year-old Koh-i-Noor, has been owned by many royal rulers. It once decorated the Peacock Throne that was used by the Mughal Emperors of India, including Shah Juhan, the builder of the Taj Mahal. Now in England, the stone is part of the Imperial Crown. Due to an alleged curse, it can only ever be worn by the royal family’s female members. Finally, there is the Regent Diamond, which was unearthed in the early 1700’s. After being owned by several rulers, it disappeared during the French Revolution. Years later, it reappeared in the sword of Napoleon. But he was unable to hold onto it for long. After being defeated by the British in the Battle of Waterloo, the once-great ruler was exiled to the tiny island of Elba in disgrace. Since 1987, the Regent’s home has been at the French Royal Treasury in the Louvre in Paris. But you don’t need to travel to France or Great Britain or Washington D.C. to see the Regent Diamond, the Koh-i-Noor, and the Hope Diamond. Replicas of these three stones plus many more world-famous diamond replicas are on display at the Hillman Hall of Minerals and Gems. While you’re there, you can also admire some expertly crafted pieces of authentic diamond jewelry that would make any gem lover’s heart skip a beat.

Even though Hillman’s diamond collection is truly amazing, I can’t help but wonder if it would have impressed someone like Marilyn Monroe. Apart from a single piece of jewelry, the diamond wedding band that was given to her by Joe DiMaggio, she had no real affinity for diamonds. Apparently, the legendary actress didn’t believe that they’re a girl’s best friend. But if she had been given the opportunity to find out about all of the other meaningful ways in which diamonds benefit our world, perhaps this screen siren might have developed a new appreciation for these precious gems. I know that I have. I’d like to think that Marilyn would have too.

Shelby Wyzykowski is a Gallery Experience Presenter in CMNH’s Life Long Learning Department. Museum staff, volunteers, and interns are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

Wulfenite and Mimetite: CMNH’s Crystal Banquet

by Nicholas Sauer

Scientific information provided by Dr. Carla Rosenfeld, Assistant Curator of Earth Sciences

Carnegie Museum of Natural History’s specimen of Wulfenite and Mimetite is one of its most fascinating. It first caught my attention because it looks so distinctly like a piece of abstract art made out of honey barbeque potato chips. It was only afterward that I discovered that the museum’s official nickname for the specimen is appropriately just that, “BBQ Chips.”

The potato-chip-shaped structures in question are thin, tabular crystals of wulfenite. A crystal is the physical, three-dimensional form that a mineral takes on in nature. The wulfenite is thin, broad, and relatively flat just like a table is, so that’s why scientists classify it as “tabular.” Sometimes, due to the conditions under which it was formed, wulfenite might also take on the shape of small pyramids.

close-up of wolfenite and mimetite specimen

The naming of wulfenite has a fascinating history itself. It was first discovered and described in the late 18th century by Austrian mineralogist Ignaz von Born (1741-1791) who gave it the name plumbum spatosum flavo pellucidum. Now, don’t be intimidated by the Latin, it is just a literal description of what von Born thought he found: yellow glasslike lead ore. Scientists later renamed the mineral wulfenite in 1845 when they discovered a deposit of it in Bleiberg, Austria. The new namesake, Franz Xavier von Wulfen (1728-1805), had spent his professional life studying the lead ores of the area. The mineral was also sometimes called melinose, after the Greek word “meli” meaning “honey,” so it is not surprising that the specimen first brought to my mind the image of honey barbeque chips in color as well as shape. While it was Austrian scientists who gave it its modern-day name, wulfenite exists in many locations around the world, including China, Arizona, and Mexico. Wulfenite even became Arizona’s state mineral in 2017. Our own BBQ chips specimen came from the San Francisco mine in Sonora, Mexico and was acquired in 1988.

However, there’s more than just wulfenite on display behind the glass in CMNH’s Hillman Hall of Gems and Minerals. If you look closer you will see groups—aggregates—of small spheres interspersed among the crystalline potato chips. These small spheres are composed of the mineral mimetite, which often forms alongside wulfenite in nature as both are leaden in their chemical makeup. Specifically, mimetite is a mineral that forms as a product of the oxidation of galena (lead sulfide) and arsenopyrite (iron arsenic sulfide). Mimetite got its name because it “mimics” the appearance of other lead-based minerals, particularly pyromorphite. The aggregates of mimetite you see at the museum have what scientists call a “botryoidal habit.” Translation: the mineral has a characteristic shape—habit—which in this case is grape-like—“botryoidal,” from the Greek. So, again, it isn’t so outlandish to describe wulfenite as “potato-chipian” when mimetite is described by scientists literally as a “cluster of grapes.” In fact, I’m starting to get a little hungry. Scientists often name their new discoveries after something familiar to them that has a similar shape or property.

But how did “BBQ Chips” come to take on its unique shape and remarkable coloration? Specific patterns of atoms that make up the minerals’ internal structure give wulfenite and mimetite their repeating and intricate form. The color of the specimens depends on their chemical composition. For instance, the wulfenite on display at CMNH gets its fiery orange hue from trace amounts of chromium lurking deep within the crystal. It is ironic that what scientists call an “impurity”—the chromium—gives the wulfenite one of its most striking and aesthetically pleasing features, its coloration. The mimetite, on the other hand, has a similar burnished orange color because of the presence of arsenic, mimetite being composed of lead chloride arsenate.

wulfenite and mimetite specimen from above

The Carnegie Museum of Natural History’s specimen of wulfenite and mimetite showcases the beauty and complexity of the natural world, the entwining of two distinct and breathtaking minerals in one display. Their bright colors and arresting shapes are the product of chemical reactions, time, and specific environmental conditions. The gastronomical names that their coloration and visible structures have garnered over the years—from “BBQ Chips” to “clusters of grapes”—make them a mineralogical feast for scientists and museum patrons alike.

Nicholas Sauer is a Gallery Experience Presenter in CMNH’s Life Long Learning Department. Museum staff, volunteers, and interns are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

References

Ascarza, William. “Wulfenite, Arizona’s State Mineral, is Theme for Current Tucson Gem Show.” Tucson.com. 12 April 2020. <https://tucson.com/news/local/wulfenite-arizonas-state-mineral-is-theme-for-current-tucson-gem-show/article_00d6cbc2-80bb-57fd-8288-9ba0f189041f.html>.

“Mimetite.” Smithsonian National Museum of Natural History. <https://geogallery.si.edu/10026354/mimetite>.

“Minerals, Crystals, and Gems: Stepping Stones to Inquiry.” Smithsonianeducation.org. 2013 <http://www.smithsonianeducation.org/educators/lesson_plans/minerals/minerals_crystals.html>.

“Mineral of the Year 2020.” Naturhistorisches Museum Wien. 2020. < https://www.nhm-wien.ac.at/en/research/mineralogy__petrography/mineral_of_the_year>.

Russell, Peter. “Oxidized Zone Minerals.” University of Waterloo. 1 March 2006. <https://waterloo.ca/wat-on-earth/news/oxidized-zone-minerals>.

“Wulfenite.” Smithsonian National Museum of Natural History. <https://geogallery.si.edu/10026003/wulfenite>.

“Wulfenite—Collected from Sonora, Mexico.” Saint Louis Science Center. 2021. <https://www.slsc.org/wulfenite-collected-from-sonora-mexico/>.

Bird Architecture on Human Infrastructure

Related Content

Carnegie Museum of Natural History Blog Citation Information

Share this post!

Share this post!

Fish and the Fourth of July?

Related Content

Carnegie Museum of Natural History Blog Citation Information

Share this post!

Cuttlefish Pass Marshmallow Test

Related Content

Carnegie Museum of Natural History Blog Citation Information

Share this post!

Share this post!

What Did Dinosaurs Sound Like?

A Brief Foray into Paleoacoustics in Science and Film

Did Dinosaurs Roar?

Paleoacoustics and Dinosaur Vocalizations

Related Content

Carnegie Museum of Natural History Blog Citation Information

Share this post!

Diamonds Are the World’s Best Friend: The Important Roles Diamonds Play in Society

Related Content

Carnegie Museum of Natural History Blog Citation Information

Share this post!

Share this post!

Wulfenite and Mimetite: CMNH’s Crystal Banquet

Related Content

Carnegie Museum of Natural History Blog Citation Information

Share this post!

Share this post!

About

Get Involved

Bring a Group

Powdermill

More Information