Am I Brilliant Blue? Lapis Lazuli Embedded in a 1000-Year-Old Woman’s Teeth

      The earth is abundant with brown, green, red, and yellow pigments but  “finding a stable blue is like willing a river to stop flowing.” In 2017, a chemist made headlines around the world for discovering the first new blue in 2 centuries, named YInMn Blue.”

         Lapis lazuli in a 1000-year-old woman’s teeth indicate she was likely a manuscript scribe who mixed her saliva with the precious ground ultramarine or lapis lazuli as she copied ancient texts.

     

    In 2014, archaeologist Dr. Anita Radini was studying the dental calculus of bodies buried in a medieval church. This hardened plaque, or tartar, is a challenge to a modern dentist, but it’s crucial evidence for researchers peering into the past. While other body parts disintegrate, teeth often stubbornly remain, and the chemical components of these teeth can offer a glimpse into our daily lives.

          At the time, Dr. Radini was scraping old teeth in pursuit of calcified starches, a useful proxy for diet. Her colleague, Dr. Christina Warinner, an expert in the evolution of ancient microbes at the Max Planck Institute, hoped to better understand oral bacteria. But, something in the mouth of specimen B78 distracted both researchers from their initial pursuits: scattered specks of a brilliant blue.

     “Can you imagine the kind of cold calls we had to make in the beginning?” Dr. Warinner told The Atlantic. “‘Hi, I’m working with this thing on teeth, and it’s about 1,000 years old, and it has blue stuff in it. Can you help me?’ People thought we were crazy.”



     Drs. Warinner and Radini assembled a multidisciplinary color detection squad. Dr. Monica Tromp, a New Zealand-based expert in particle analysis with the Max Planck Institute, took on the task of identifying the blue hue’s origin. Dr. Alison Beach, a history professor at The Ohio State University, a Smith College graduate, and an expert in medieval German women’s role in copying illuminated manuscripts, offered essential cultural context. Drs. Warinner and Radini also consulted a scholar of medieval trade about the economic context in which B78 lived. What they found brought smiles to everyone’s faces

    B78, the authors determined, was a woman who lived sometime between 997 and 1162 A.D. She died in middle age, between 45 and 60 years old. Except for the blue color in her mouth, she “was otherwise unexceptional,” according to the study authors. But in a new paper published this week in the journal Scientific Advances, the color detectives showed B78 had lapis lazuli in her mouth—evidence she was a highly-skilled manuscript scribe in a time when most people assumed illumination was the exclusive domain of men.

     “It didn’t surprise me, it thrilled me,” says Dr. Beach,  co-author in the study. Dr. Beach has studied female manuscript makers since graduate school, hoping to make the public understand their role in producing some of the most elaborate artworks of the age. But because most of the volumes are unsigned—and the few that are signed were signed by men—making the case for women’s role in these spaces has always been a challenge. But the blue found in B78’s teeth is stronger evidence than one might expect.

A self-portrait of Guda, a 12th century nun and illuminator, signed "Guda, a sinful woman, wrote and painted this book." The source of the blue-green color is unknown.

   
     "Blue was, is, and will continue to be the hardest color to find or create."

      In the medieval period, artists had five sources of the color: ultramarine, azurite, Egyptian blue, smalt, and vivianite. The most prized of these was ultramarine, more commonly known in its ground and purified form as lapis lazuli. Found only in one region of Afghanistan, for millennia lapis lazuli demanded the same price as gold. It wasn’t, in other words, something you’d expect to find in random medieval dental calculus. “This isn’t a kind of paint you just give to someone who’s learning,” Dr. Beach says (contrary to the suggestion of an outside reader evaluating the paper before publication, who believed the woman was just a janitor cleaning up after the real manuscript makers).

     The study entertains other possibilities—that B78 was undergoing lapidary medicine, where she swallowed pigments for her health, or that she engaged in “devotional osculation,” where Christians kissed paintings as part of worship. But the way the blue pigment was distributed deep into the teeth, in fairly consistent layers over time, indicated B78 was one of the “modest and pious women who quietly produced the books of medieval Europe,” the authors wrote. Specifically, Dr. Beach thinks B78 and her colleagues would have been narrowing the point on their fine-tipped brushes with their mouths, mixing lapis lazuli into their dental plaque in the process.

     Dr. Beach and other medieval historians are optimistic this method will apply broadly to other manuscript makers of the era. “I had never heard of using dental calculus as a window on somebody’s everyday life,” Dr. Beach says, but now that researchers know where to look, the possibilities are limitless. “There’s so few sources that medieval historians have for ordinary people. This one clue of the lapis lazuli opens a whole window on the life of an ordinary women in a period in which we have almost no sources,” Dr. Beach adds. “She’s not a queen, she’s not a duchess. She’s just a person who lived and worked and died.”

      Blue is my favorite color, Dr. Beach is a Smithie, and I enjoy mazarine minerals, especially lapis lazuli. How about you? 

       Happy Blue Year!

Steph

Nine ways to draw our ever bluer state:





Blue-Leaved Begonias and Fibonacci Golden Spirals

       Some leaves of certain species of begonias in Malaysia are luminescent blue in order to harvest maximum energy in low-light conditions.

      The begonias’ chloroplasts, which use photosynthesis to convert light into fuel, have a repeating structure that allows the plants to efficiently soak up light. This is important for plants that live on the shady forest floor. 



     The structure acts as a “photonic crystal” that preferentially reflects blue wavelengths of light and helps the plant better absorb reds and greens for energy production, researchers report in the October 24, 2016 issue of Nature.

     Colors in plants and animals typically come from pigments, chemicals that absorb certain wavelengths, or colors, of light. In rare cases, plants and animals derive their hues from microstructures. In begonias, such tiny, regular architectures can be found within certain chloroplasts, known as iridoplasts. As light bounces off these structures within an iridoplast, the reflected waves interfere at certain wavelengths creating a blue, iridescent shimmer.

     These contain regularly spaced stacks of three to four 'thylakoids' - which resemble a photonic crystal and strongly reflect wavelengths of light between 430 and 560 nanometers.

      The thylakoids look very similar to the artificial structures commonly used to make miniature lasers that control the flow of light. Studies of low light gathering in begonias may prove useful in improving the sharpness of color on computer and Smart phone screens.

      The iridoplasts concentrate these specific wavelengths onto the plant's photosynthetic apparatus, increasing the efficiency of its photosynthesis by 5 to 10 percent. 

      Those structured chloroplasts also offer a survival benefit; they help the plants collect light. In a hybrid of two species, Begonia grandis and Begonia pavonina, the structures enhance the absorption of green and red wavelengths by concentrating these rays on light-absorbing compartments within the iridoplasts. Importantly, the structures slow the light. The “group velocity,” or the speed of a packet of light waves, is decreased due to interference between incoming and reflected light. The slowdown gives the plant more time to absorb precious sunbeams.

     “These iridoplasts can basically photosynthesize at low-light levels where normal chloroplasts just simply could not photosynthesize,” says study coauthor Dr. Heather Whitney, a plant biologist at the University of Bristol, England. Iridoplasts, however, can’t hold their own in bright light. So begonias also have standard chloroplasts, which provide energy in plentiful sunshine. Iridoplasts act like “a backup generator” in dim conditions,  Dr. Whitney says.

      The Fibonacci Golden spiral on some begonia leaves is a luminescent bonus!



Blue and Fibonacci, what a duo!
Steph

Partial Ellipsis of the Sun's 100th Post: Lichen it to a Litmus Test

     Today's post is inspired by the discovery that the dyes used in litmus paper are derived from lichen. I'd lichen that to paronomasic perfection (thanks SuperZee) for our 100th week. 

      Gadzooks! That must mean Partial Ellipsis of the Sun's two-year anniversary is just around the corner. 

     "Litmus" is derived from Old Norse lit-mosi, from litr "dye" + mosi "moss." Litmus paper is one of the things I have used but never investigated its origin, via either the word origin or the actual compounds.

       A variety of lichen such as this one, Roccella tinctoria, a relatively bland-looking organism that is a combination of algae or cyanobacteria (or both) living among a fungus in a symbiotic relationship,

and contains the compounds to make the colorful dark-purplish, red, and blue dyes used in litmus powder (the compounds are used also for dyeing rugs and fabrics).

        A brief refresher of high school chemistry: The pH scale ranges from 0 (a strong acid which turns blue litmus paper red) to 7 (neutral) to 14 (a strong base which turns red litmus paper blue).

        pH, which stands for potential Hydrogen, can actually be measured more accurately with a pH meter or pH paper giving more specific numbers all along the logarithmic pH scale from 0 to 14.

     

        In politics, of course, a litmus test is a question asked of a potential candidate for high office, the answer to which would determine whether the nominating official would proceed with the appointment or nomination.

        Sadly, we cannot dip politicians in lichen to determine their pHenomenal true and honest answers to critical questions.

      At least, not yet.

       I'll stick to chemistry. And geology. And biology. And physics. And astronomy. . .I lichen these topics much more (magnified lichen below):

      Thanks very much for your support these past nearly two years to the pHilosophy and pHun that is "Partial Ellipsis of the Sun."

       I truly appreciate your being my litmus test for interesting, inspiring, controversial, funny, and paronomasic topics.

pHinally and gratefully,
StepH ;-)

     I can only stay focused on the lichen on the rock for so long. . .Here's some sandstone from today's walk. You can almost hear the wind blowing. . .

     

Calving: Ice or Cow. . .And Is There A Connection?

          For this week's PEOTS, how about choosing between ice calving

      or cow (or moose or seal or whale) calving?

      Hmmmm. Let's go with ice calving. Check out this largest filmed ice calving event at the Ilulissat Glacier in Greenland. 

      Ice calving, also known as glacier calving or iceberg calving, is the breaking off of chunks of ice at the edge of a glacier, iceberg, ice shelf, or crevasse. The ice that breaks away is classified as an iceberg, but may also be called a growler or bergy bit.

     Growlers are smaller pieces of ice, generally rising less than a meter above water level, that make a growling animal sound as they move in the ocean. Bergy bits are mini icebergs that rise up to 4-5 meters above the water level. 

        

         Ice calving has gotten lots of attention lately as a result of global warming (See the 2014 documentary Ice Chasing).

        And perhaps watch it with this kind of beer growler:

       Do you suppose there's any connection between the sound of cows birthing and the sound of ice calving (the latter term first originated in Denmark in 1837), growlers and all?

Enjoy that ice calving blue; looking forward to your insights,

Steph

Bridgmanite and Smithsonite: One Shocks, the Other Doesn't

          Bridgmanite is the most abundant mineral on earth, comprising 38 percent of earth's volume, primarily in the lower mantle at depths below 400 miles (670 km), but was just recently given a name this year.

         

          

          Bridgmanite is a magnesium iron silicate (Mg,Fe)SiO3 which shows the effect of being shocked by impact as part of a meteorite hitting the earth, as seen in this hand specimen from Australia:

  

          and more pronounced in thin section:

  

        It was named for Percy Bridgman, a Nobel Prize-winning physicist. Before being identified in a meteorite, the mineral was loosely referred to as a silicate perovskite:

          By geologic naming convention, a mineral cannot be named until actually examined in hand specimen (hard to do 400 miles deep). So, American researchers looked at a meteorite sample that had fallen in Australia in 1879 as a likely candidate for sampling material similar to this deep mantle mineral. They used a test that involved the use of a micro-focused X-ray beam in conjunction with electron microscopy. And, thus, a mineral was named in the:

              November 28, 2014, edition of Science

      In contrast to the shocked appearance of bridgmanite, the strikingly smooth, pearly luster of smithsonite, a zinc carbonate, shows the effect of slow, undisturbed crystal growth:

           The crystals often form in grape-like clusters referred to as botryoidal:

          Zinc carbonate or zinc spar (ZnCO3) or smithsonite, was named after James Smithson, the same chemist and geologist who donated money for the Smithsonian Institution. Smithsonite has a hardness of 4.5 and a specific gravity of 4.4 - 4.5. In addition to the green, and blue-green colors, it also occurs in lustrous, pearly pink crystals:

       Though you may have guessed my favorite, the blue botryoidal, smithsonite clusters:

     How about you? Were you shocked to learn bridgmanite was only recently named? That smithsonite occurs in so many pearly, lustrous, botryoidal forms and in so many colors?

Looking forward to your often shocked and shocking comments (as well as your pearly luster),

Steph