Museums don’t know everything about the objects in their collections. As Curator of Ancient Glass at The Corning Museum of Glass, one of my responsibilities is to research the objects in our ancient glass collection and ensure we have accurate and current information about them.
In summer 2020, I began to study the two dozen or so pieces in our collection that are made of obsidian, a naturally occurring volcanic glass, which were attributed to North American origins. Some of our obsidian pieces were displayed in the Glass in Nature case, with the naturally occurring glasses, while others were in the Study Gallery, with objects from the ancient Mediterranean. We didn’t have good labels or information in either gallery space.
The information we had in our database was similarly meager. Almost all the objects entered the collection in the 1950s and 1960s. The information we have about them had not been evaluated or updated since those initial records were created decades ago. For example, one group of objects was said to have come from the midwestern United States, because the person from whom we acquired the objects lived in Kansas. Several large blades were said to have been made somewhere in the United States, at some point within a several hundred-year span of time, with no apparent justification for those attributions. Two flat, oblong objects described as mirrors were given a date of 1000 CE but were said to have possibly come from Central America, or possibly North America. That’s a pretty specific date for a very large area!
I wanted to begin a journey to better understand these objects and the people who made and used them hundreds of years ago. Indigenous peoples of the ancient Americas did not create glass from sand, but they did use obsidian for tools and ceremonial objects.
To help me learn more about the origins of our pieces, I reached out to several archaeologists who study Native American obsidian. I eventually connected with Dr. Steven Shackley, professor emeritus at the University of California Berkeley, who operates a lab in Albuquerque, New Mexico. Shackley explained that, unlike man-made glass, obsidian sources are easy to identify using non-destructive scientific analysis. This is because obsidian is produced during volcanic eruptions, so each eruption has a unique chemical fingerprint. Scientists like Shackley have used these fingerprints of obsidian objects worked by humans to trace them back to the original geologic sources. As a result, scientists have learned that obsidian objects are often found hundreds of miles from the geologic origins of the obsidian.
Shackley and his colleagues primarily study objects that have been scientifically excavated at archaeological sites. Through these studies, archaeologists have been able to associate specific obsidian sources with specific groups of people who lived at different moments in time. By knowing where the obsidian itself comes from, we can build a hypothesis about who likely made the object and when.
Shackley offered to analyze Corning’s obsidian objects, so our Conservation and Preparator teams packed the objects securely in custom-built boxes and sent them off to Albuquerque.
His resulting report was filled with surprises. A seemingly modest blade from the “midwestern” group discussed earlier actually came from an obsidian source in central Mexico. The quality and color of this Pachuca obsidian made it especially prestigious. This type of obsidian was exchanged over long distances – as far north as Oklahoma – although we don’t know where our blade was found.
On the other hand, the source of the oblong “mirror” which had been dated to 1000 CE turned out to be from Glass Buttes, Oregon, a location well-known to modern rock collectors for its gorgeously streaked, gem-quality stone. The oblong shape of our mirror is also definitely more modern than a thousand years ago.
I was disappointed to find out that another group of obsidian blades which our records said had come from Syria instead came from Arizona. I had previously identified these as among the oldest man-made objects in our collection, but they are likely much more recent.
But that disappointment was countered by the identification of some new contenders for the “oldest object.” One large biface blade comes from Bodie Hills in central California. Indigenous people in California used this obsidian source 5,000 years ago, that’s 2,000 years before people in Egypt and Syria began to experiment with man-made glass.
A small projectile point made from Obsidian Cliffs stone, in modern Oregon, may even be older. Obsidian from this source has been found at sites occupied 10,000 years ago and from as far north as British Columbia, Canada, and as far east as the Ohio River Valley.
This investigation is only the first step in beginning to better understand the obsidian objects in our collection and the people who made and used them, and I look forward to continuing to learn more.
For more information about obsidian in North America, see:
- Levine, Marc N., and David M. Carballo, eds. 2014. Obsidian Reflections: Symbolic Dimensions of Obsidian in Mesoamerica. Denver: University Press of Colorado.
- Saunders, Nicholas J. 2001. “A Dark Light: Reflections on Obsidian in Mesoamerica.” World Archaeology 33 (2): 220–36.
- Shackley, M. Steven. 2005. Obsidian: Geology and Archaeology in the North American Southwest. Tucson: University of Arizona Press.