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Photo of Walter Fasnacht Walter Fasnacht as seen on Mediterranean On the Rocks: Copper Island

Click on Walter's photo to read a brief bio.

q What is the name of the ancient Greek dice (usually made from sheep bone),and where can I get more information on what types of games were played with them? (Question from Karen, a math and science teacher)

A The name of the dice in Greek is ASTRAGALOS, plural astragaloi. The Romans called the Astraglus, in German it is Astragal, in English knuckle bone. I will compile a list of literature, as it is a very interesting object for teachers of math, especially for statistics. Please check back to see that list of literature posted with this answer.

q Why was copper so valuable that the people used all the trees to make charcoal for the smelters? Weren't the trees valuable, too?

A This question is very difficult to answer, because it does not touch on science, technology or monetary systems so much, but rather politics, power or even greed. For a better understanding, let's transfer this question word by word into the 21st century AD - and please answer it: Why is individual mobility so valuable that people use up all the oil of this planet to drive a car? Isn't fossil energy valuable too?

q I think that the show was really cool and I have a question about reason for smelting. What uses were there for copper other than for making the little dice that would help "predict" someone's future? (Question sent by Michael, St. Pauls School)

A The use of copper by mankind has to be regarded throughout the history of metallurgy, that is over the last 8000 years: In the Stone Age, when copper was discovered, it was used for jewelry, weapons and tools. Both copper weapons and tools were superior to the ones made of stone. In the Bronze Age, tin was added to copper to make an even harder metal. At that time, even swords, helmets and arrow heads were made of bronze. Tools for wood working, like axes, or knives etc. were also made of bronze. In the Iron Age, when the site of Almyras was operated, bronze became the metal for jewelry, figurines, statues, religious objects and vessels - and of course, as you have seen, of toys. This was the case from about 600 BC through Roman and Medieval times. Today, copper has kind of a renaissance, in modern technology of telecommunication.

q It is easy to find native copper as one of the constituents of bronze, but how did the the early metallurgists ever learn to smelt tin? At my last visit to a museum, I noticed that ceramics and smelting appeared to be evolving at a similar pace. Was early metallurgy an outgrowth of ceramics? (Question sent by Roger)

A Watch out! "It is easy to find native copper" is only true for North America. Nowhere else in the world was this the case in prehistoric times. So Near Eastern and European cultures went through a whole sequence of copper smelting techniques, from the easy copper carbonates to the difficult copper sulfides, before tin was even known (between 3500 and 3000 BC). The reduction of tin oxides to tin metal is certainly easier than making copper from chalcopyrite.

But, you are right, ceramics were the foundation of all metallurgy! Temperatures of below 1000 degrees Celsius were used for most ancient ceramic products, but the potters must have come above that temperature by mistake or at certain stages of the firing of pots. The key product for a thorough research of this transition would be the first inert waste product produced by mankind, the slag. But archaeologist unfortunately tend to look at nice things first!

q I am interested in your practical project on metal smelting. Can you recommend any literature on the subject? I'm interested in primitive metal smelting and casting from a practical perspective. Can you recommend literature on iron as well? (Question sent by David)

A Three recommended books to read more about primitive smelting of copper and iron are:

R.F. Tylecote: A History of Metallurgy (1979)

R.F. Tylecote: The early history of metallurgy in Europe (1987)

P.T. Craddock: Early Metal Mining and Production (1995)

q I REALLY enjoyed the "Copper Island" segment of the program. One question that came to my mind was: How much time did it take all together to make the bronze dice? (Question sent by Amy, 6th grade student, St. Paul's School)

A This is a very complex question, if you really calculate every little step to get there. Let's say you want two pounds of copper, plus 3 ounces of tin to make 10 nice astragali, bronze dice (bronze objects were not green in antiquity, they were shiny and looked like gold).

Somebody will have to smelt the copper and the tin from two separate ores, and at two separate places. There is not a milligram of tin in the rocks of Cyprus, so it had to be brought from Turkey, or as far as Kasachstan. Once the metal was organized, the clay moulds for the casting had to be made. This takes a few hours, but then they needed to be dried for several days. The actual casting of the dice is done in twenty minutes, that is the time to melt two to four pounds of bronze in a crucible you saw. Then you break the clay mould, take the cast object out and polish them with a piece of cloth, sand and water. All in all, if you think yourself back 3000 years, with all the effort behind such simple objects (imagine you would have to make a more complicated object, like a bronze cauldron with beautiful handles, or a bronze brooch), bronze objects must have been very valuable, almost like gold today.

q Is smelting a possible hazard to the environment? If so do people today still smelt copper and tin enough to worry about it? (Question sent by Sarah)

A The hazard of smelting to the environment is a terrible reality - in antiquity and today! You can read more in: Science, No. 265 (1994), p. 1841-1843 and in Science, No.272 (1996), p. 246-249, by Hong, S., Candelone, J.-P., Patterson, C.C. and Boutron, C.F. They found the pollution of ancient copper and lead smelting in Greenland Ice cores! Today, the pollution due to metal production is much greater than in antiquity ! But the global changes due to burning up fossil fuel are an even more serious threat to worry about.


Scientific American Frontiers
Fall 1990 to Spring 2000
Sponsored by GTE Corporation,
now a part of Verizon Communications Inc.