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Melle, industrial Centre of the Carolingians: about the only preserved early medieval Silver Mine in France

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Silver was incredibly precious in the early Middle Ages due to the fact that it was extremely expensive to get out of the earth. How this was done, we will see in Melle, the only preserved silver mine of the medieval epoch.

 

Come along with us on our journey through the world of money. Today we are stopping in Melle. We are in the years between 814 and 840 AD.

 

M-E-T-A-L-L-V-M: Metallum is written on the reverse of this Carolingian denarius. Metallum is Latin and does not only mean metal and ore but mine as well.

 

Only slightly different sounds Metullum, as the Romans called the city where this coin was minted and the required silver had been won. Metullum was an industrial center of the Carolingians where then state-of-the-art technology was deployed to win silver.

 

Today, Metullum is called Melle and is a quaint village located not far from Poitiers. Most citizens make a living from agriculture. Just a few tourists are coming to visit the marvelous churches that have been built long ago to welcome the vast number of Jacobean pilgrims that used the Via Turonensis to get to Santiago di Compostela.

 

Hardly any visitor knows that Melle has an even bigger attraction in store. There, you can visit the only mine from early medieval times that is preserved in its original state.

 

This is called a geode. A geode is a hollow structure that has a uniform mineral outer shell. Metullum had many of these geodes around which an ore was concentrating the miners called galena or lead glance.

 

Lead glance is a sulfide that derives its name from its high content of lead. It often contains silver as well, albeit in such small an amount that the traditional technologies developed by the Greeks and Romans were not efficient enough to exploit the ore.

 

In Carolingian times, it was different. The markets required the new coins bearing the name of the king. On this coin, Louis the Pious guarantees for the value of the money with his name and his effigy. His portrait with the laurel wreath and the paludamentum around the shoulder strongly resembles Roman models.

 

1.6 grams is the weight of our silver coin. That does not sound very much.

 

To win 2 grams of silver, however, one kilogram of galena had to be processed. And to gain one kilo of galena, it took about 100 kilograms of rock, on average. An enormous quantity, in the light of the fact that everything had to be done manually, without the technical means of today.

 

The miners used to enter a vertical drift and to climb down ladders. Deep down, they dug their narrow horizontal galleries, carefully following the veins in the stone und thus limiting the amount of waste rock.

 

To facilitate the work, the miners resorted to fire-setting underground. They lit a fire quite close to the rock, in order to heat it, thus creating a thermal shock which would make the rock become brittle and crack eventually.

 

If they were lucky, the rock split and smaller chunks fell to the ground. If were not so lucky, that happened only when they got near the rock again.

 

Anyhow, in order to blast one cubic meter of rock 1,140 kilograms of wood were needed. In terms of our 2 grams of silver that means: 95 kilograms of wood had to be burned in order to win the required amount of rock.

 

Once the toxic fumes had disappeared, the miners returned to the gallery, removed the brittle ore from the rock face and sorted the chunks that had fallen to the ground. The waste rock was left behind in the pit. Today, the giant mine dumps of the Middle Ages have become snowy-white mountainscapes, all furred-up due to chalky water dripping down.

 

The galena was transported to the surface. It was sorted and picked manually, a work women also were involved. Then, the heavy metal-containing ore was separated from the lighter waste material by wet-sifting.

 

Afterwards, the material was roasted on an open fire.

 

Finally, the thus prepared ore was split into its components, silver and lead, in the refining hearth. The method was based on the fact that lead has a much lower melting point than silver. Besides, it takes a lot of effort to oxidize silver whereas base metals react with lead relatively quickly.

 

People in Carolingian times, therefore, were able to win silver with a purity of 99.9% in the so-called cupellation process.

 

It goes without saying that this, too, required wood or charcoal, respectively. We have no idea how many trees were cut down but it seems safe to assume that the number must have been incredibly high.

 

Minting the coins at the Melle Mint was only the final step at the end of a time-consuming, laborious and costly process. On this coin we can see the tools that were needed for the minting: the dies for both the obverse and the reverse as well as two hammers.

 

Louis the Pious was the last emperor to rule the entire vast empire of Charlemagne alone. Thereafter, it was divided into West and East, into France and Germany. Both parts, however, continued to mint the denier and the pfennig, respectively. The monetary system of the Carolingians lasted for centuries until it was replaced by the decimal system.

 

Thank you for listening. And you can find more podcasts about coins and money on the Sunflower Foundation Web page.