A crystallographic structure of a prehistoric bronze from Sardinia wins 3rd prize in the DNRF’s Photo Competition 2021

30. March 2021

The winner of the 3rd prize in the DNRF’s Photo Competition 2021 is a picture of a microscopic fragment of an ankle on a small bronze figure from Sardinia from about 900 BC. The small piece of metal is a mixture of copper and tin and has been exposed to a crystallographic examination that highlights the colorful and patterned structure that may also hide important information about the craftsman behind it, as well as the trading networks from the time the bronze figure was made.

Foto: Heide W. Nørgaard, Moesgaard Museum.
Photo: Heide W. Nørgaard, Moesgaard Museum.

A patchwork of endless burned shadings and clear, almost luminous, colors constitute a captivating abstract pattern. Is it a cartographic segment, a negative air photo, or something completely different? The winner of the 3rd prize in the DNRF’s Photo Competition 2021 is the picture of a crystallographic structure of a microscopic fragment from an ankle of a prehistorical bronze figure from Sardinia.

“The picture shows a fragment of a bronze figure from the end of the Sardinian Bronze Age around 900 BC. The bronze fragment is a part of some samples from the rest metals that are mainly from the fragment of the hands and feet from small statues that were made in the so-called Sardinian Nurage Culture. We would like to know how the statues were manufactured because it is obvious to us that there is a big difference in the quality. This is very important information for archaeologists and especially for archaeometallologists, as it gives us an idea about how good the quality of the metal is, and how good the alloy is,” said Heide Nørgaard.

A crystallographic is a thin grinding of a small metal sample, which is taken from a bigger metal object in order to see the metallographic structure. An analysis of the structure gives researchers the possibility of seeing how the object was created back in the day, which can then also reveal important information about the prehistoric craftsmen and their society.

“We have a chance to understand the quality of the prehistoric crafts with a crystallographic structure and their technical abilities at that time. If you only observe the object from the outside, then you only see the craftsmen’s taste and their way to express themselves. But through a crystallographic, we can gather a lot of information that is otherwise lost, because we can see how it is made from the inside. For example, this picture shows us how the object is cast, and you are able to see that because of these tree-like structures – they actually look a little like Christmas trees. There is the big one in the middle, which is very classical, if you take a closer look, you can actually see it all around,” said Nørgaard.

The overall approach for this kind of sample that Nørgaard and her research colleagues use is called a metallographic and originates back to the 1960s. Besides being used in archaeologic contexts, the method is often used in the industry when you need good quality and approved metals for all sorts of machines. By looking at the metals structure, you can assess if it is good and strong enough to do the functions that are needed of it.

Sensuous manufacturing techniques

Bronze is an alloy of copper and tin and the distribution between the two is essential for the metal’s quality. It wasn’t possible to tell how the percentage had to be distributed between the two metals to create the best possible object at the time the object was made in Sardinia. Back then you used your senses to create a better understanding. For example, the Bronze Age’s craftsmen could see it based on the color and the smell once they started the alloy process, and then they could see how fast it would melt.

“Many of the prehistoric craftsmen had an amazing understanding of how the metal reacts, and to get this knowledge of what metal can do from a sensuous perspective is extremely fascinating. This picture is a specimen of this, as it shows, how perfectly the craftsman behind it understood his material,” said Nørgaard.

The perfect casting presupposes that the one who manufactured the object knew which percentages of copper and tin were necessary to create a metal that flows enough and that gets around all the small corners of the mold that was used for the figure concerned. Besides that, the person had to have knowledge of how long the object needed to cool down, as well as the exact temperature.

“You can see the required knowledge of this craft in the tree-like forms that has shaped itself in the picture. They only shape themselves like that if you have the right alloy and the right temperature. It means that they were fully in control of the manufacturing process that was required to get the best results,” said Nørgaard. She continued:

”I have chosen exactly that picture, not only because it is colorful and beautiful, but because it shows us the incredible skills that were needed to create this object. In other words, it is not only beautiful to look at, it is also beautiful craft.”

The only one in Denmark

Besides a few other archaeologists in Europe that have the same background in metalcraft—among others, a female archaeologist in France and another in England—Heide Nørgaard is the only one in Denmark in her research field. She was previously a goldsmith and started out by studying archaeology in Berlin. She had an idea about wanting to work with metal. She wrote her Ph.D. thesis in Denmark, specializing in how the craftsmen of the Bronze Age manufactured bronze objects, and whether you could see who was behind the single object. Every craftsman works differently, which can be seen on the object once you look at certain styles, ornaments, and technical knowledge that dominated their time. All this is reflected in the object through a technical and craftsman’s fingerprint.

“By examining every little thing of the object, I can see that the print in the bronze object has its own specific form. Once you put down a print, it is a hand movement that started on a certain time and ends on another, and maybe it has been interrupted in between. The way you move your hand is unique. If I compare many little different errors and fingerprints in this kind of decoration on an object, I will be able to see some patterns, and if I examine them more closely, I will be able to conclude a specific technique that creates that pattern. And because the print distinguishes itself from others, you can distinguish different craftsmen that are behind the creation,” said Nørgaard.

The goal for Nørgaard’s work is to get a deeper knowledge of the people who lived back then and maybe even being able to trace whether it was the left or right hand that was used for the creation 3500 years ago Such knowledge could give us the possibility of seeing which kind of contacts the people had that enabled them to manufacture these objects. In her newest project, Nørgaard is tracing the metal trade in the Bronze Age and exploring what kind of trading network existed in the years 2000 BC to 1000 BC to get all that bronze to Denmark and Southern Scandinavia.

“Southern Scandinavia didn’t have its own copper and tin back then. All the metal that was used was imported from places that were at least a three-day journey away. This knowledge is so new and important for our society because it shows that already 3000 years ago, we had a big network which reached far beyond our borders and far beyond the small society that we live in, “said Nørgaard.

Connection between Sardinia and Denmark

Nørgaard is researching how the metals came to Scandinavia and how the craft could be connected to other parts of the world. In their newest publication, Nørgaard and her research colleagues have expanded the time span from the very first metal that came to Denmark; clearly, about 1600 BC, a new metal source was found in the Italian Alpine area. Therefore, from 1600 BC, the network and trade were considerably changed. They were first dominated by metal from the Slovakian area, then changed over to a completely new metal source from the area around the Alps. This opens up the possibility that the Norwegian Bronze Age may have been involved in a metal trade that may also have used the metal from Sardinia.

“If we look at this visually, we have the characteristic Viksø-helmets with horns at the end of the Danish Bronze Age. At the same time, around 900 BC, these little bronze figures are also found. The resemblance can be seen in the small warrior figures that also have helmets with horns. And this is where we hope that the project, in which the object in the picture submitted to the DNRF also dates back to, in the long run can create a connection between the small figures with the horned helmets from Sardinia and our Viksø-helmets in Denmark.”

Read more about Heide W. Nørgaard’s winning photo in a press release from the Moesgaard Museum (in Danish) here

Go’ morgen Danmark ran a feature on the DNRF’s Photo Competition 2021 on 3/22/2021. You can watch it at TV2 Play through the streaming service (in Danish) here