DID PALEOLITHIC ARTISTS HAVE THE BLUES?

Azurite mineral deposit. Internet image, public domain.

I have posted previous columns about the use of the color blue in rock art and other ancient art (click on ‘color’ in the cloud index at the bottom). Recently, one column was about the discovery of indigo on grinding stones dated 34,000 years ago. Now we have evidence of the use of a blue mineral pigment, azurite, in Europe from about 13,000 years ago.

Doctor Izzy Wisher of the Department of Archaeology and Heritage Studies, and the Department of Linguistics, Cognitive Science and Semiotics of Aarhus University, Denmark, wrote: “Blue pigments are absent in Palaeolithic art. This has been ascribed to a lack of naturally occurring blue pigments or low visual salience of these hues. Using a suite of archaeometric approaches, the authors identify traces of azurite on a concave stone artifact from the Final Palaeolithic site of Mühlheim-Dietesheim, Germany. This represents the earliest use of blue pigment in Europe. The scarcity of blue in Palaeolithic art, along with later prehistoric uses of azurite, may indicate that azurite was used for archaeologically invisible activities (e.g. body decoration) implying intentional selectivity over the pigments used for different Palaeolithic artistic activities.” (Wisher et al. 2025:1) The evidence was found as trace deposits in between the grains of a grinding stone, presumably used to grind the azurite as a pigment, or somehow shape it.

Blue pigment residue found at site in Central Germany. Photograph by Izzy Wisher.

Detection of these mineral traces depended upon a suite of techniques available to modern, cutting-edge laboratories. “To characterize the composition and crystalline structure of the blue residue, and to determine whether it resulted from the processing of a blue pigment, we deployed a suite of archeometric methods: micro- and x-ray florescence (μXRF/XRF); scanning electron microscopy coupled with electron dispersive spectroscopy (SEM-EDS); particle induced x-ray emission (PIXE); Fourier transform infrared spectroscopy (FTIR); fibre optic reflection spectroscopy (FORS); multi-collector inductively coupled plasma mass spectrometry ((MC-)ICP-MS); and multiband imaging.” (Wisher et al. 2025:5) Presumably this is why the paper lists a team of fifteen scientists involved in this investigation.

Azurite deposit on artifact. Internet image, public domain.

The team “confirmed the traces were from the vivid blue mineral pigment azurite, previously unseen in Europe’s Paleolithic art. Their results are published in the journal Antiquity. ‘This challenges what we thought we knew about Paleolithic pigment use,’ says lead author of the study, Dr. Izzy Wisher from Aarhus University. Until now, scholars believed Paleolithic artists predominantly used only red and black pigments – no other colors are present in the art of this period. This was thought to be due to a lack of blue minerals or their limited visual appeal.” (Phys.org 2025) I certainly have to disagree with the ‘limited visual appeal’ statement. What is more beautiful and attention grabbing than a bright blue stone? Remember the importance of turquoise throughout human history. Now, shortage of natural sources makes much more sense because azurite is not that common.

Azurite ore deposit from Serbia. Internet image, public domain.

"Azurite is a soft, deep-blue copper mineral produced by weathering of copper ore deposits. During the early 19th century, it was also known as chessylite, after the type locality at Chessy-les-Mines near Lyon, France." (Wikipedia)

The three areas of blue residue present on the sandstone layer of the stone artefact from Mühlheim-Dietesheim. Area A, due to its more accessible location on a flatter area of the sandstone, was the primary focus of archaeometric analyses. Scale bar is 50mm (figure by authors). Figure 1, page 3, Wisher et al., 2025.

I only know of two older examples of the human use of blue pigment. “’It’s nearly the oldest blue pigment in the world – the only other known example that predates our case is from Siberia, where traces of blue-green pigment were found on figurines dating to around 19-23,000 years ago,’ Dr. Izzy Wisher, lead study author and archaeologist at Aarhus University in Denmark, told IFLScience. There is also evidence from Georgia, dating to 32,000–34,000 years ago, of people potentially creating a purplish-blue pigment from crushed indigo plants (Isatis tinctoria), the same plant that would later give rise to the dyes behind blue jeans. Outside of these rare cases, however, true blue pigments are exceptionally scarce in the prehistoric world.”(Hale 2025) We do not know what this azurite was to be used for, but it was obviously possessed and used for something by these ancient peoples.

So, it would seem that the conclusion has to be that yes, they had the blues, but apparently did not use them in their pictographic art.

NOTE 1: The above reference to IFLScience refers to the website https://iflscience.com.

NOTE 2: Some images in this posting were retrieved from the internet with a search for public domain photographs. If any of these images are not intended to be public domain, I apologize, and will happily provide the picture credits if the owner will contact me with them. For further information on these reports you should read the original reports at the sites listed below.

REFERENCES:

Hale, Tom, 2025, Dating Back 13,000 Years, One Of The Earliest Uses Of Blue Pigment Has Been Unearthed, 29 September 2025, https://www.eflscience.com. Accessed online 29 September 2025.

Phys.org, 2025, Europle’s oldest blue mineral pigment found in Germany, September 2025, https://phys.org/. Accessed online 29 Septembe 2025.

Wikipedia, Azurite, https://commons.wikimedia.org/w/index.php?curid=164155

Wisher, Izzy et al., 2025, The earliest evidence of blue pigment use in Europe, Antiquity, https://doi.org/10.15184/aqy.2025.10184. Accessed online 19 September 2025.

 

CANADIAN CARVED STONE PILLAR – ANCIENT OR MODERN?

The Vancouver carved stone. Photograph from CBC News.

A supposed First Nations artifact has been discovered on a beach near Vancouver, British Columbia. This one is a conundrum, the artifact may or may not actually be indigenous but it is impressive. A carved stone face found on a rock on a beach at Vancouver, British Columbia, Canada, has been identified as an old artifact created by First Nations people, and also claimed by a contemporary artist to be his creation. So, which is it?

"A carved sandstone pillar discovered on Dallas Road Beach last summer is an Indigenous artifact once used in rituals by the Songhees and Esquimalt First Nations, says a Royal British Columbia Museum curator of archaeology." (Kloster 2021) So, it has been authenticated. This seems pretty cut and dried, right? 

The artifact was discovered on the beach in January 2021 by a resident out walking. "Last week, the Royal B.C. Museum announced it had discovered an Indigenous artifact used in rituals by the Songhees and Esquimalt First Nations. The museum said the 100-kilogram oblong pillar with a carved face on its edge had been examined by an archeology curator. After consulting with local communities and looking at anthropological records, the curator came to the conclusion the artifact was likely related to ceremonies involving the feeding of the dead." (Diclson 2021) The discoverer certainly did the right thing in notifying the Royal British Columbia Museum.

Coastal Salish style petroglyphs, Bella Coola, British Columbia, Canada. Photograph by Wolfgang Zintl.

This artifact was studied and pronounced authentic by Royal British Columbia Museum curator of ­archeology Grant Keddie. “It’s very likely a special stone that was used in rituals and ceremonies, he said, explaining that Coast Salish peoples had “weather specialists. They were believed to have “special powers to draw the salmon in when they were late, or you could undertake rituals [with] certain stones to change the weather to make it good for fishing, to make it worse for your enemies, He speculates the pillar once stood near the edge of a cliff above the beach where it was found until parts of the cliff came down in a landslide.” (Haldoupis 2024) While this seems to make sense, given ethnographic records of the people of the area, this is only surmise, not proof.

This is in the area of prehistoric occupation by the Coastal Salish First Nations People. Now I have a few images of rock art by Coastal Salish peoples and none of them resemble this carving in any degree so my first reaction was to doubt the authenticity of the stone carving. The handling of the eye and mouth seem quite out of character for Salish art work.

Artist's photograph claiming authorship of the carving. Photograph on right by Ray Boudreau, from the Times Colonist.

Then, to make things even more confusing, a local artist claimed he had carved the figure. "Ray Boudreau posted a photo of a similar rock carving on the Times Colonist Facebook page, saying it was his carving and he thought it had been stolen." (Dickson 2021) However, the photograph he provided does not quite match the carving in many details, but then the photograph shows a piece that looks unfinished. 

Coastal Salish stone carving - Txwelatse. Photograph from the Burke Museum, Seattle. 

If it helps cast light on this question somewhat similar carved stone figure was held at the Burke Museum in Seattle. The stone T'xwelatse, an ancestor of the Chilliwack (Ts'elxweyeqw) - one of the the Stolo tribes in the Fraser Valley - is a man who was born thousands of years ago and transformed into a four foot high granite statue as punishment for mistreating his wife. This figure has since been returned to the Stolo tribes and has been displayed at their cultural center gallery.

So, we have contradicting claims for the authenticity of the artifact. Is it an authentic Salish relic, or is it not? At this point I could not begin to tell you. You might have to figure this one out for yourselves.

NOTE: Some images in this posting were retrieved from the internet with a search for public domain photographs. If any of these images are not intended to be public domain, I apologize, and will happily provide the picture credits if the owner will contact me with them. For further information on these reports you should read the original reports at the sites listed below.

REFERENCES:

Dickson, Louise, 2021, Provenance of stone pillar in question after artist says he created the rock carving on Victoria beach, 1 February 2021, Victoria Times Colonist. Accessed online 18 September 2025.

Haldoupis, Julia, 2024, Carved Stone Pillar Found on B.C. Beach Identified as an Indigenous Artifact, 29 March 2024, https://archaeologyworlds.com/. Accessed online 18 September 2025.

Kloster, Darron, 2021, Stone pillar found on Dallas Road beach likely once used in Indigenous rituals: Curator, 27 January 2021, Victoria Times Colonist. Accessed online 18 September 2025.

HAWAIIAN PETROGLYPHS RE-EXPOSED ON OAHU BEACH:

 

Wainae Beach petroglyphs, Oahu, Hawaii. Internet image, public domain.

On September 10, 2016, I wrote about a group of ancient Hawaiian petroglyphs discovered on Wainae Beach, Hawaii. They had been first noticed by tourists from Texas. Now, a new report of the petroglyphs on Wainae Beach has come out, apparently the same group that had been reported previously. As weather shifts the beach sand it appears that they are periodically exposed and then covered again.

Wainae Beach petroglyphs, Oahu, Hawaii. Internet image, public domain.

An Associated Press report, written by Jennifer Kalleher stated that “Hawaiian petroglyphs dating back at least a half-millennium are visible on Oahu for the first time in years, thanks to seasonal ocean swells that peel away sand covering a panel of more than two dozen images of mostly human-looking stick figures.The petroglyphs are easy to spot during low tide when gentle waves ebb and flow over slippery, neon-green algae growing on a stretch of sandstone. This is the first time the entire panel of petroglyphs are visible since they were first spotted nine years ago by two guests staying at a bayside U.S. Army recreation center in Waianae, about an hour’s drive from Honolulu.” (Kalleher 2025)

Wainae Beach petroglyphs, Oahu, Hawaii. Internet image, public domain.

“This reemergence is connected to patterns of seasonal weather. From May to November, Pacific storms churn the waters, scouring sand from beaches and occasionally bringing archaeological features that were obscured by sediment into view. Over time, the sand will eventually return, burying the carvings until they reappear during a shift in coastal dynamics once again. Specialists monitor the petroglyphs site, which lies within the grounds of a U.S. Army recreation area. The shoreline itself is open to the public, but complete access to the adjacent property requires military identification. This has created an ongoing controversy about how to preserve this part of Hawaii’s cultural heritage and make it more widely available.” (Radley 2025) From the reports it appears to me that nature and the U.S. Army are already doing a pretty good job of preserving the petroglyphs, and I really don’t go along with the part about “make it more widely available.”

NOTE: Some images in this posting were retrieved from the internet with a search for public domain photographs. If any of these images are not intended to be public domain, I apologize, and will happily provide the picture credits if the owner will contact me with them. For further information on these reports you should read the original reports at the sites listed below.

REFERENCES:

Kalleher, Jennifer Sinco, 2025, Early Hawaiian petroglyphs on a beach are visible again with changing tides, 24 July 2025, AP News. Accessed online 26 July 2025.

Radley, Dario, 2025, Ancient Hawaiian petroglyphs reemerge on Oahu’s shores after years of being hidden, https://archaeologymag.com (online). Accessed online 26 July 2025.

 

 

PALEOLITHIC ARTIFICIAL MEMORY SYSTEMS:

We have long considered ancient rock art including cave paintings to be data. I also include carved bone and ivory as well as portable carved and modified stones. The authors of this new paper have a modified way of looking at these records. They refer to them as Artificial Memory Systems (AMS), suggesting that after they had been created they could be visited again later to retrieve data from them.

While they focused on bone and ivory it seems to me that their approach could just as well be used looking at painted caves, or any other rock art. “Artificial Memory Systems (AMS) encompass devices that record, store, transmit, and retrieve coded information beyond the brain, via external representations. AMS can be anything from the notches on a gunslinger's pistol, tracking past success, to the symbols on and data encoded within the Voyager spacecraft's golden record, detailing a snapshot of Earthling knowledge and culture.” (Jackson 2025) This is all true, although it is a pretty broad field of examples.

 A. and B. – marks on bone made by modern butchery. From Courtenay et al., 2025,  Figure 1, page 3.

The methodology the team used will be to analyze two groups of marked artifacts, the Paleolithic and what they refer to as ethnographic. The ethnographic artifacts are much more recent and we have actual ethnographic data about their meanings. “Current scientific knowledge suggests humans are the only species to manufacture and use these tools. While a number of artifacts dating back to the Middle Paleolithic have been considered to be early instances of AMS, conclusive and systematic evidence of this function is absent. Here we contrast the spatial distribution of markings on these potential early AMSs to other Paleolithic artifacts displaying butchery and ornamental marks, as well as ethnographically recorded cases of AMS. We find that both eth­nographic and Upper Paleolithic AMSs are endowed with systematically different signatures that distinguish them from the other artifacts. These findings suggest that modern humans in at least Africa and Europe had sophisticated cognitive capabilities for information storage and retrieval, providing insights into the possible development of quantity-related cognition.” (Courtenay et al. 2025) Many researchers have considered the question of numeration in these examples of ancient art, from dots and lines among the animals on cave walls, to grooves on a boulder as a given but the question of what they do or do not count is constant.

 

C.and D. – decorative engraving in the form of zoomorphic (C) and geometric (D) motifs. From Courtenay et al., 2025,  Figure 1, page 3.

Statistical analysis was applied to the Paleolithic bone markings. “The present analysis has shown that the spatial distribution of different types of markings on bone are separable, with distinct patterns emerging for butchery activities, figurative or abstract representations, and potential AMSs; whether the latter be ethnographic examples, or Paleolithic instances interpreted as such from previous studies. These studies have proposed that four distinct factors, in isolation or com­bination, may play a role in creating codes allowing for the storage of information in an AMS; the number of marks, the accumulation of marks over time, their spatial organisation and arrangement, as well as their morphology. To date, the identification of potential Paleolithic AMSs has been based mainly on the technological analysis of marks.” (Courtenay et al. 2025)

E.  and F. – possible AMS. From Courtenay et al., 2025,  Figure 1, page 3.

Having used statistical methods to analyze the Paleolithic examples, the team then used the same methods on more recent artifacts for which ethnographic records are available. “The examined ethnographic datasets included examples of notched sticks, some of which exhibit quantity-related representations, and some that strongly suggest some form of expressive quantification. They are documented from 20th -century artefacts from Muacapenda and Muatchondo (Angola), tally sticks from Medieval England, as well as 19th -century notched wooden artifacts from the Yakun­bura community of the Dawson river (Australia). This raises a plausible interpretation for these artifacts, related with the emergence of quantitative cognition in our species. Although these artifacts present no additional discernible information about their function based solely on the mark­ings beyond the data that has been collected ethnographi­cally or historically, our statistical analyses show that they share many properties with the potential Paleolithic AMSs in our sample. An important remaining question, however, is to determine what aspects of expressive quantification might be involved in Paleolithic AMSs, since quantifica­tion is a multifaceted phenomenon that encompasses a wide range of features and cognitive mechanisms.” (Courtenay et al. 2025) Comparing the results of their study of both groups of artifacts, the team concluded that the Paleolithic markings were indeed capable of recording data, but since we have no knowledge of their languages it is unlikely that we will ever be able to retrieve that data.

G. and H. – known AMS. From Courtenay et al., 2025,  Figure 1, page 3.

Of course we are still using AMS, we just have very technologically different systems nowadays. “Writing systems, recorded music and images stored digitally in computer code represent the most modern form of AMS, utilizing the most complex mix of language and technology ever created, while essentially relying on the simplest binary system of notches and dots to encode.” (Jackson 2025) Of course writing systems, recorded music and digital images rely on considerably more complicated tools to achieve their function. Indeed, I am typing this into a Lenovo laptop computer. My actions in this are not really more complicated than carving notches in a bone would be, but I am only able to do this because someone went to considerable trouble to manufacture my tool, much more complicated than a rock flake.

So, do these markings encode data? If the obvious fact that the marks were produced on purpose by someone with an idea behind them can be considered data, then yes, they do. I really don’t know what this gets us, however. We already believed this. It sort of strikes me as arguing about the difference between red and scarlet. I suppose it is comforting to know that their statistics back up what we believed all along.

REFERENCES:

Courtenay, Lloyd Austin, Frencesco d’Errico, Rafail Nunez, Damian E. Blasi, 2025, Identifying potential palaeolithic artificial memory systems via Spatial statistics: Implications for the origin of quantification, Archaeological and Anthropological Sciences 17 (171). https://doi.org.10.1007/s12520-025-02286-4. Accessed online 5 August 2025.

Jackson, Justin, 2025, Searching for Artificial Memory Systems in ancient humans with spatial statistics, 5 August 2025,  Phys.org online. https://phys.org/news/2025-08-artificial-memory-ancient-humans-spatial.html. Accessed online 5 August 2025.

THE MILKY WAY IN ROCK ART:

 

The Milky Way. Vera Rubin Observatory photograph.

It is almost universally accepted that ancient cultures were very interested in the heavens, and we can assume that the prehistoric creators of petroglyphs and pictographs were also fascinated by questions of the universe. It could not have been possible to not be fascinated by the Milky Way.

Nut, Egyptian sky goddess. Internet image, public domain.

Among the most prominent features of the night sky is the side view of our galaxy that we call the Milky Way. Ancient cultures had to have an explanation for it that satisfied their world view and mythology. “The Egyptians, for examples, may not have been the only culture to link the Milky Way to a sky goddess who gives birth to other gods and, especially, other celestial objects.” (Graur 2024:37)

Citlalicue, sky-goddess. Internet image, public domain.

Peoples of the Americas had their own beliefs concerning the Milky Way. “Several of the pages in the Codex Borgia, a pre-Colombian pictorial manuscript composed by the Tlaxa-caltec people of the Puebla-Tlaxcala Valley in Mexico, include images of elongated beings covered with stars. These beings have been identified as the Milky Way as well as the goddess Citlalicue (Star Skirt), the “… goddess of the stars …”, and the mother of several gods, including the Venus god Quetzalcoatl. Quetzalcoatl is shown cutting his way out of the belly of Citlalicue; this and other, similar scenes in Co-dex Borgia 29-46 are interpreted as Venus crossing the Milky Way.” (Graur 2024:37)

Similar views of the Milky Way are found across Mesoamerica (Milbrath, 1999: 41). The dead of the Yucatec Maya travel along the Milky Way at night (Sosa, 1985: 432). The Quiché Maya see the Galaxy as two of four cosmic roads. Of these, the Black Road (Q’eqa b’e) or Road of Xibalba (Ri b’e xib’alb’a), which is identified with the dark band of the Milky Way’s Great Rift, leads to the underworld (Tedlock, 1985: 36, 337, 354). Similarly, the Lacandón call the Milky Way the “… white way of our true lord …”, Hachäkyum, the ruler of heaven populated by the dead.” (Graur 2024:39)

Mayan two-headed sky monster, from Clopan, altar 4,  Late Classic Period. Image from Mary Miller and Karl Taube,The Gods and Symbols of Ancient Mexico and the Maya, Thames and Hudson, London, 1993.

The ancient Maya saw the Milky Way as a serpentine monster with a head at each end. “Specifically, the two-headed monster known as the Celestial Monster or Cosmic Monster. This particular supernatural creature usually has either a crocodilian or sky band body, but in at least one example, cloud scrolls form the body. - - Most commonly, the Bicephalic Monster frames scenes of accession or rulership for the Maya, but its intrinsic meaning may be to represent the arc of the heavens, the front head being identified with Venus, pulling behind it the fleshless head of the Sun in the Underworld .” (Miller and Taube 1993:45) This is considerably more picturesque than many other beliefs, but then the Maya did have amazing imaginations and left us many images of them.

First Nations people in North America had a range of beliefs concerning the Milky Way. “Many Native American peoples across North America view the Milky Way as a road along which the spirits of the dead travel to the afterlife. The souls (tasoom) of the Cheyenne are said to travel toward the home of Hemmawihio (The Wise One Above), an all-knowing high god re-presented by the Sun, via the Milky Way, which is known as ekutsihimmiyo (Adamson Hoebel, 1960: 86–87). The Lakota name for the Milky Way is Wanáǧi Thacháŋku, the Spirits’ Road, which the Lakota follow to heaven when they die (Hollabaugh, 2017: 70–72). The Pawnee come to this life as the children of stars and, when they die, become stars once more. The stars of the Milky Way are the ancestors of the Pawnee moving from this world to the next (Pawnee Nation Tribal Historic Preservation Office, pers. comm., 2022)..” (Graur 2024:39) The idea that the Milky Way is a road or a path is a very common belief all around the world.

Chaco Canyon petroglyph panel. Photograph by Suzan Bradford.

Suzan Bradford's photograph overlaid against the Milky Way. Image by Robert Juhl.

Back in 2014 Robert A. Juhl sent me a PowerPoint presentation that he had created based upon a rock art photograph from Chaco Canyon that had been taken by Susan Bradford. In this presentation he likened the petroglyphs panel in the photograph to details of the Milky Way in the region of Scorpius in the night sky. When he superimposed the petroglyphs panel over this section of the Milky Way a crack across the panel seems to conform with the ‘Great Rift’ in the Milky Way, and he could match up a number of other details in the panel and the Milky Way. Additionally, although Juhl does not make this claim in his PowerPoint, the other features on the panel could represent constellations in that section of sky.

In the area of the American southwest tribes, the Milky Way is known as Ashes placed across the sky, or the Great Snowdrift in the sky by the Zuni people. (Miller 1997:183) In the design for a Navajo sand painting in the Shooting Chant Father Sky on the left side shows the Milky Way across his chest as a row of connected diamonds. (Miller 1997:187) But, most tribes in North and Central America connect the Milky Way with a path arcing across the night sky.

 

Rochester Creek petroglyph panel. Photograph Peter Faris, August 1993. Reminiscent of Nut arched across the sky, with a push me-pull you in the upper left corner to represent the Mayan two-headed monster?

With that definition in mind I will present as a possible representation of the Milky Way the great panel at Rochester Creek, near the junction with Muddy Creek near Emery, Utah. The arc in the panel might be seen as representing the Milky Way, and the creatures scattered around it might represent the constellations as identified by the people. As I said above, this is only a possibility, the arc in the panel is often presented as a rainbow as well, but the Milky Way and surrounding constellations might be a better explanation of the other figures on the panel. In any case, it is an interesting question and kind of fun to speculate on.

NOTE: Some images in this posting were retrieved from the internet with a search for public domain photographs. If any of these images are not intended to be public domain, I apologize, and will happily provide the picture credits if the owner will contact me with them. For further information on these reports you should read the original reports at the sites listed below.

REFERENCES:

Graur, Or, 2024, The Ancient Egyptian Personification of the Milky Way as the Sky-Goddess Nut: An Astronomical and Cross-Cultural Analysis, Journal of Astronomical History and Heritage, 27(1), 28-45.

Juhl, Robert A., 2013, The Milky Way in Chaco Rock Art, Version 18. PowerPoint presentation.

Miller, Dorcas S., 1997, Stars of the First People, Pruett Publishing Co., Boulder, Colorado.

Miller, Mary, and Karl Taube, 1993, The Gods and Symbols of Ancient Mexico and the Maya, Thames and Hudson, London.

SECONDARY REFERENCES:

Adamson Hoebel, E., 1960. The Cheyennes: Indians of the Great Plains. New York, Holt, Rinehart and Winston.

Milbrath, S., 1988. Birth images in Mixteca-Puebla art. In Miller, V.E. (ed.), The Role of Gender in Pre-Colombian Art and Architecture. Lanham, University Press of America. Pp. 153–178.

Milbrath, S., 1999. Star Gods of the Maya: Astronomy in Art, Folklore, and Calendars. Austin, University of Texas Press.

 

Tedlock, D., 1985. Popol Vuh: The Mayan Book of the Dawn of Life, Revised Edition. New York, Simon & Schuster.

COULD THE CAVE ARTISTS ACTUALLY SEE THEIR COLORS – EVEN BLUE?

 

On July 12 and 19 of this year (2025) I published a two part look at color perception among ancient peoples titled Could the Cave Artists Actually See Their Colors – parts 1 and 2. These explored theories that ancient people perceived fewer colors than we do today. While I do not agree with any of those positions I did have fun exploring the topic. Now I have found a paper that helps cast light on that question and may help provide an answer. 

Isatis tinctoria L. Internet image, public domain.

The discovery was made in Dzudzuana Cave, in Georgia, in the Caucasus. “In the foothills of the Caucasus, archaeologists have recovered something unusual from Dzudzuana Cave: tiny traces of indigotin, the molecule that produces indigo blue. The residues clung to pebbles used as grinding tools 34,000 years ago. They came not from food, but from the leaves of Isatis tinctoria L. – a plant better known as woad.” (anthropology.net 2025)

Isatis tinctoria. Photograph botanic.cam.ac.uk.

The evidence was found in grinding stones. “The leaf epidermis fragments were found entrapped in the topography of the used surface of unmodified pebbles, in association with use-wear traces. Although their bitter taste renders them essentially inedible, the leaves have well-recognised medicinal properties and contain indigotin precursors, the chromophore responsible for the blue colour of woad, a plant-based dye that is insoluble in water.” (Longo et al. 2025:1) Indeed, it is woad that is traditionally used in dying the denim for blue jeans.

“This is the first evidence that Upper Paleolithic groups intentionally processed a non-nutritional plant to extract compounds for purposes beyond survival. For archaeologists, it is a rare window into how Homo sapiens looked to plants not just for calories, but for color, healing, and meaning.” (anthropology.net 2025) So now the question is whether the I. tinctoria was ground for medicinal uses, or to obtain the blue colorant, or both.

“The ingestion of non-nutritional plants containing medicinal secondary metabolites was identified in 47,000-year-old Nean­derthal dental calculus, while tentative evidence for poison 40,000 years ago was recovered from Border Cave, South Africa. Medicinal plants are reported from a number of Palaeolithic sites in the Caucasus; however, it is challenging to demonstrate that these were ingested and/or intentionally processed. To date, there is no evidence for the extraction of dyes from organic materials in the Palaeolithic; the known colourants (red, yellow, black and white) are all pigments of mineral origin apart from charcoal. They are highly resistant to ageing, with little apparent degradation and known to have been used in Palaeolithic art and for other purposes. For example, ochre is known in various applications such as tanning leather or skin, as a preservative, as insect deterrent and as skin protection.” (Longo et al. 2025:2-3)

Grinding stones with traces of Isatis tinctoria L. leaves. Photograph from PlosOne.

Also “this is the first time indigotin — a blue secondary compound, also known as indigo — has been identified on such ancient artifacts. The molecule forms through a reaction between atmospheric oxygen and the natural glycoside precursors in Isatis tinctoria L. leaves, released from the cellular vacuoles. This proves that the plant, despite not being edible, was intentionally processed as early as 34,000 years ago.” (Ca’ Foscari University of Venice (Press Release), 2025)

 

“Although a significant number of plants naturally contain useful secondary metabolites, many require complex processing to access these and make them usable. Even in the case of food, some nutritious plants require extensive leaching, roasting and/or pounding to eliminate toxins, while extraction of useful medicinal secondary compounds demands a deep knowledge of plants since many can be both medicinal and poisonous, with only the correct processing and dosage making the difference. The processing of plants cannot be simply assumed or ignored as it formed part of the complex tapestry of Paleolithic life. Nonetheless, to demonstrate the use of plants, exhaustive analytical studies are required and studies such as those pre­sented here, is one way to achieve this.” (Longo et al. 2025:15-16) I think common sense allows us to infer a considerable range and variety of plant use during the Paleolithic.

Microscopic trace of indigotin. Image from PlosOne.

“Many plants have extensive medicinal properties including anti-inflammatory, anti-tumor, antimicrobial, antiviral, anal­gesic, and antioxidant and there is extensive evidence for the use of these, not only in human traditional medicine, but also across the animal kingdom. All animals, and even insects, self-medicate. In the case of chimpanzees, they sometimes prepare the plants prior to consumption; Sumatran orangutans are known to apply to wounds a mashed concoction of Fibraurea tinctoria leaves. Today, the roots of I. tinctoria and other indigo-bearing plants are used in medicine because they contain flavonoids and the leaves contain indigoid-precursor molecules that have preserva­tive, antiseptic, repellent, and protective properties. It is therefore entirely within the behavioral context of humans, from all Paleolithic periods, to use plants to self-medicate.”  (Longo et al. 2025:17)

Indigotin ground from Isatis tinctoria. Photograph from archaeology.org.

“I. tinctoria is also known as a source of indigotin, a well-established blue chromophore obtained by the oxidation of precursors naturally present in the cells of the leaves. The use of I. tinctoria to obtain a blue hue is well known, and this knowledge extends into later prehistory. The use of this plant has been recorded as dye since Egyptian times, the earliest written source being the Papyrus Graecus Holmensis (also known as the Stockholm papyrus, retrieved in the XIX century). However, while the possibility exists that I. tinctoria was transformed into woad dye and used during the Early Upper Palaeolithic, there is currently no archaeological evidence for this. However, and more broadly, color was  known, in particular in rock art where red, yellow, white and black are present across the Eurasian continent and the Indonesian archipelago from around 40,000 years ago. Blue is a relatively rare color in nature and to the best of our knowl­edge, blue pigment (mineral-based) from Palaeolithic contexts has only been reported for Siberian figurines.” (Longo et al. 2025:17-18) Organic based paints (i.e. plant-derived) tend to disappear through oxidation and weathering over the millennia. I. tinctoria may have been used as a colorant for rock art but we may never know it.

Given that no known evidence remains of the use of I. tinctoria as a colorant from this long ago so it may well be that the intended use was medicinal, however, the fact that the people there were engaged in grinding it in preparation for something would seem to be proof that they could see it. So, the question of whether ancient painters could see blue or not 34,000 years ago is closed – as I said before, they could.

NOTE: Some images in this posting were retrieved from the internet with a search for public domain photographs. If any of these images are not intended to be public domain, I apologize, and will happily provide the picture credits if the owner will contact me with them. For further information on these reports you should read the originals at the sites listed below.

REFERENCES:

Anthropology.net, 2025, The Blue Shadows of Dzudzuana, 2 September 2025, https://anthropology.net. Accessed online 3 September 2025.

Ca' Foscari University of Venice (Press Release), 2025, Traces of blue indigo on 34,000 year old grinding tools suggest Paleolithic plant use scenarios, https://phys.org/news. Accessed online 2 September 2025/

Longo, Laura et al., 2025, Direct evidence for processing Isatis tinctoria L., a non-nutritional plant, 32–34,000 years ago, 9 May 2025, PLOS One, https://doi.org/10.1371/journal/pone.0321262. Accessed 3 September 2025.

A COMET PETROGLYPH AT LOS ALAMOS:

I have written before on the subject of comets pictured in rock art here on RockArtBlog. I find the concept of an astrophysical manifestation like a comet being recorded in this way to be eminently reasonable, something as amazing as a close approach of a comet might well spark the desire to make a record.

Los Alamos petroglyph panel. Photograph by Bruce Maase, 2013.

One apparently memorable comet appearance was in 1264 AD. This one was supposedly seen pretty much worldwide, and mentioned in records. According to Herman E. Bender “Unambiguous images of comets in North American rock art are rare. What is or may well be even more rare to non-existent was/is the ability to date the images. This potentially changed with discovery in or about 2013 of a comet pictograph near Los Alamos, New Mexico. The comet in the pictograph was identified by a scientific team as the Great Comet of 1264 AD. Backing up the claim, European and Asian medieval comet records firmly indicated the comet had entered eastern Orion in mid-August and had five tails. Because three stars in a row, i.e. Orion’s ‘belt stars’, were indicated on the rock art panel along with the comet and its five tails, the comet in the pictograph was dated to mid to late August, 1264 AD.” (Bender 2023:21)

Los Alamos petroglyph panel. Photograph by Bruce Maase, 2013.

Here Bender is correlating the vertical row of three dots below the supposed image of the comet to the belt of the constellation Orion. 

One interesting identifying feature of the comet portrayal is that it is shown with five lines of dots that are taken as its tails. “Five tails was a salient feature of the Great Comet of 1264 AD. The Korean records stated that, ‘On a chia-hsi~ day in the seventh month of the fifth year of WSnjong [26th July] a comet was observed at the NE. Its tail, which measured 7 to 8 ft, gradually divided itself into five branches pointing towards the NW.’ Further corroborating the five tails time-line for August 17 (1264 AD), the Korean record went on to state that, ‘On a jen-yin day in the eighth month [23rd August] the [five] branches reunited and the tail increased in length.’ The European records leave no doubt that the comet sported five separate tails, but also echo Asian records of where the comet was seen with its five tails on the early morning of August 17, 1264 AD, i.e. ‘between the Dog [Sirius and Canis Major] and Orion’.” (Bender 2023:21-22) I have so far been the actual dating method used to reach this conclusion, however, Bruce Masse (2013) implies that it was estimated based on the position of the comet to a supposed indication of the constellation Orion on the panel. This position was also found in the Korean record.

Woodblock print depicting the great comet of 1264, dated 15th century. Internet image, public domain.

The remarkable appearance of this comet would have been memorable indeed. Donald K. Yeomans (2007) reported that “on July 26, Chinese observers reported the tail spanning 100 degrees.” This is obviously an extremely impressive manifestation with it spanning 100 degrees across the arc of the sky. This appearance was well recorded with J. R. Hind citing over three dozen contemporary sources in his 1884 book On the expected return of the great comet of 1264 and 1556.

Adoration of the Magi, Giotto di Bondoni, 1301. From Karam, 2017, p. 72.

As I had stated above, I find the concept of an astrophysical manifestation like a comet being recorded in this way to be eminently reasonable, something as amazing as a close approach of a comet might well spark the desire to make a record. A more famous example of such a record is the fresco painting Adoration of the Magi by Giotto di Bondoni in 1301 in the Scrovegni Chapel in Padua, Italy. In this, Bondoni shows the magi before the Holy Family in the manger with the Star of Bethlehem shown in the form of a comet.

Having been lucky enough to have seen a few comets in my life I can well understand the urge to leave a record of such a wondrous occasion. While I have not always totally agreed with Bender’s analyses in other things I can find no reason to disagree with this one. Congratulations to all involved in winkling out the facts to this fascinating story.

NOTE 1: If you wish to refer to P. Andrew Karam’s (2017) book on comets be sure to check pages 66 and 67 where he has included my photograph and field sketch of the great comet from the famous panel in Chaco Canyon.

NOTE 2: Some images in this posting were retrieved from the internet with a search for public domain photographs. If any of these images are not intended to be public domain, I apologize, and will happily provide the picture credits if the owner will contact me with them. For further information on these reports you should read the original reports at the sites listed below.

REFERENCES:

Bender, Herman E., 2023, The Great Comet of 1264 AC in Rock Art – Two Views from North America, Hanwakan Center for Prehistoric Astronomy, Cosmology and Cultural Landscape Studies, Inc., Fond du Lac, Wisconsin, USA. Accessed online 14 September 2024.

Hind, J. R., 1848, On the expected return of the great comet of 1264 and 1556, Published by G. Hoby, 123 Mount Street, Berkeley Square, London. Accessed online 6 August 2025.

Karam, P. Andrew, 2017, Comets, Reaktion Books, London.

Masse, W. Bruce et al., 2013, A Probable Ancestral Pueblo Comet Petroglyph at Los Alamos National Laboratory, PowerPoint presentation at IFRAO 2013 conference, American Rock Art Research Association, Glendale, Arizona. Accessed online 7 August 2025/

Yeomans, Donald K., 2007, Great Comets in History, from Solar System Dynamics, Jet Propulsion Laboratory, California Institute of Technology. Accessed online 6 August 2025.