Wednesday, January 11, 2012


Hello My Friend and Welcome.

In our first post on metallurgy we looked at the discovery and uses of gold, the king of metals. If you missed it, you can find it HERE. By the way, we’ve decided to present the metals in their order of usage by ancient populations.

Today we move onto copper which represented a giant leap for ancient man. Whereas gold was freely strewn about the creeks and riverbeds waiting for man to pick it up, copper exists only as an ore. The Copper Age became a practical reality when men mastered not only the ability to identify copper ore in its natural state, but also the understanding of how to smelt and work the metal into usable items.

Copper is one of the rare metals that’s found in nearly pure concentrations in nature. This is most likely where the ancients began. Gold casting was known by that time and it’s easy to imagine people of that era gathering chunks of copper into a pot and treating it pretty much as they did gold. When they achieved essentially the same result, they were off and running. Copper metallurgy is well-documented in the Middle East and into Egypt as early as 4,000 BC.

The Israelites mined copper and used it extensively. The Bible refers to the importance of copper: “Men know how to mine silver and refine gold, to dig iron from the earth and melt copper from stone.” (Job. 28:1-2) Leaving Solomon and skipping ahead about ten centuries, we find the famous Copper Scroll. Found at Qumran in 1952, it is arguably the most intriguing use of copper in ancient Israel. Unlike the other Dead Sea Scrolls, which were written on animal skins or papyrus, the Copper Scroll is engraved on thin copper sheets. Clearly, this was done because of the importance of the information it contained. The Copper Scroll contains a list of 64 underground hiding places throughout the land of Israel.
These deposits are identified as containing gold, silver, aromatics, and precious manuscripts. They are believed to be treasures from the Temple at Jerusalem that were smuggled out of Jerusalem during the Roman barricade and hidden away for safekeeping. To date, none of these treasures has been found. While this sounds like a Hollywood adventure film, the idea should not be dismissed out of hand.

An Ancient Copper Bowl with Embossed Animals

In the earliest of times, copper items were made by cutting, curving and hammering with a stone mallet on a stone anvil. These ancient metalworkers made an important discovery. Metal hardens under prolonged hammering, but can be brought back to its initial ductility by heating with no change in shape. Many ancient objects were manufactured through alternate cycles of hammering and cooking, with a final hammering to obtain the necessary hardness.

The simplest way to make a copper bowl consisted og placing a thin copper disc on a wooden block hollowed out to fit the profile of the required object. This method dates back to the pre-dynastic periods of Babylonia and Egypt. A second technique was known as raising. A copper disc the same diameter as the finished pot, was laid over the horn of an anvil and hammered into the desired shape.

Though copper knives have been found, the metal’s softness made it at best marginally useful. Ancient man also made copper arrowheads and copper spear points. But the best use of copper was for utilitarian household items such as bowls, pots, cups and similar objects. Being metal, if it was dropped, it might dent, but it would not shatter like a fired clay pot.

Ancient Copper Coin

There were other popular uses of copper beside weapons and pots. Another giant step for mankind occurred when commerce moved from barter to a currency based system. The very earliest “coins” were simple lumps or disks of metal. Romans in the 6th through the 3rd centuries BC used copper lumps as money. At first, just the copper itself was valued, but eventually the concept of a uniform coinage supplanted it. Ancient copper coins have been found all over the world. The use of copper in coinage was widespread in ancient times and continues to this day.

Modern Copper Coinage

Copper was also widely used to make jewelry of all types. Ancient artwork depicts women wearing copper bracelets, rings, necklaces, and earrings. Highly polished copper was also used as a somewhat inefficient mirror. “For now we see in a mirror dimly, but then face to face.” (1Cor. 13.12)

Two advances in metalworking enhanced the decorative use of copper, enameling and the verdigris finish. Enameling is done by applying fine glass powder to a metal and then heating it in a kiln to a temperature sufficient to melt the glass. We know that glass was widely used in the ancient world. The first attempts at enameling probably consisted of dripping molten glass onto a piece of copper. When the results proved unsatisfactory, some genius decided to grind the glass and re-melt it in order to fuse it to the copper substrate.

Verdigris, copper with a greenish tarnish was extremely popular throughout both the ancient Greeks and Roman world. Originally the copper was deliberately tarnished so that it could be scrapped off and used as a colorant. The green color in eye shadow came from copper oxide or Malachite, copper carbonate. Pottery glazes also relied upon powdered copper oxide. For a turquoise they added wood ash, for a green they mixed in powdered lead.

As modern as they sound, items such as wall plaques, sundials, and other outdoor decorations with a verdigris finish were favored in the ancient garden…perhaps because of its green color. This tarnish effect can be achieved by long term exposure to sea spray, which produces a copper-chloride patina. The same effect can be produced faster by suspending the item within a covered pot above boiling vinegar. Vinegar, readily available in the ancient world, is a dilute form of acetic acid. This process yields a verdigris patina of copper-acetate.

In modern times, the verdigris finish is most commonly produced with spray paint.

Next time we’ll return to our series on Foods of the First Century and look at Fruits and Nuts.

Until then, we wish you Peace and Blessings.

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