February 5th 2019


Here is the quarry in Mostamarka. It is now filled with water. Photo: Tom Heldal.
Whetstones from Mostadmark have journeyed with the Vikings throughout the world. Evidence of a large-scale extraction of whetstone has been discovered in a forested area, south of Hommelvik in the municipality of Malvik.

- In all likelihood, the quarry was active for over several hundred years, from about year 700 into the Middle Ages. Vikings used these rocks to sharpen knives, axes and swords,” says Tom Heldal, a senior researcher at the Geological Survey of Norway

Participating in this interdisciplinary research were geologists Tom Heldal (NGU) and Øystein Jansen (University of Bergen) and archaeologists Irene Baug (University of Bergen) and Dagfinn Skre (University of Oslo). Their findings have been recently published in the Journal of Maritime Archeology.

In-depth analysis

For many years, geologists and archaeologists have puzzled over the source of the whetstones found in the Viking villages of Ribe, Denmark and Hedeby, Northern Germany. The whetstone artifacts are typically fine-grained schist, often purple to blue-purple color. 

- We speculated that these rocks originated in Norway, but now we have verified the extraction site for the schist whetstones which were widespread in the Viking era," explains Dagfinn Skre, who is an archaeologist at the University of Oslo.

Waste heaps of schist near the site of the old quarry.

The whetstones were subjected to chemical and mineral composition analyses with help from Jasmine Schönenberger and Ann E. Karlsen at NGU’s laboratory. From the lab results, the researchers determined the origin of the schist: Mostadmarka which is located between Malvik and Selbu in Trøndelag.

Export commodities

Since the early 700’s, whetstone has been extracted Mostadmark and swiftly found its way to southern Scandinavia, to places like Ribe, south-western Jylland, Denmark.

Here is the whetstone material near the quarry in Mostadmarka.

Archaeologist Irene Baug explains that during the Viking era, there was increased exploitation of natural resources, including rock quarrying, where supply exceeded local demand. Large-scale production of whetstone in Mostadmarka developed already in the 8th century. 

- The export of whetstone during this period is one of earliest signs of long-distance trade of commodities from Northern Scandinavia during Viking era,” says Baug, adding that:

- Essential goods and commodities were distributed to a larger market. Whetstone was one of the most important tools of the Viking Age, in the household and for craftspeople. The stone was necessary for grinding and honing all types of tools, including knives, axes, needles, arrows and swords.

Shipped out from Lade

Archaeologist Irene Baug
working with the whetstone
artefacts from Ribe:
Photo: Øystein Jansen.

Earlier research had already suggested that most of whetstone artifacts found in northern Europe that dates from the Viking Age originated in Norway. However, it was assumed that from around the 9th century, all the extraction took place in quarries discovered in Eidsborg, Telemark. 

- The production in Mostadmarka began around 100 years before the large-scale extraction of Whetstone in Telemark," reports Baug.

The distribution of Mostadmarka whetstone has now also given scientists new insight into trade interaction between producers and consumers, as well as sea transport routes along the West coast of Norway from year 700 and onwards.  

- The whetstones were likely shipped out of Lade in Trondheim. From about year 800-1000, Lade was a storing place for goods belonging to the Lade Earls, important political agents in Norway during this period. This connects the distribution and trade of whetstone to high-level individuals in Viking Age, says Irene Baug.

Cultural heritage site

Researcher Tom Heldal asserts that the new information has strong implications for the future plans for the quarry in Mostadmarka.

- Age automatically qualifies the quarry as a cultural heritage site under the Cultural Heritage Act, which is the Norwegian law that protects such archeological sites. This means that it would be illegal to initiate actions that could damage, destroy or modify the quarry in any way. Digging into the stone waste heaps around the quarry would also be prohibited,” says Heldal. 

Researchers plan to determine the complete size of the quarry and stone waste heaps. They will also officially inform the cultural heritage authorities in Trøndelag about this new discovery. However, many questions remain unanswered: Who was behind the extraction of rock? Who owned the quarries? Who was responsible for the far-reaching distribution of the whetstone?

Here is the original article published in the Journal of Maritime Archaeology.

Gravel along the creek conceals both rock waste and whetstone fragments.