An Introduction to Alloys Bonus: You keep me alive, copper!
Well, there’s been some copper coming through the shop lately, so I thought I’d give you a primer on pure copper.
As we’ve covered before, copper is the main component of both brass and bronze. It’s an element in the transitional metals group, atomic number 29. The symbol for copper, Cu, is shortened from the Latin cuprum, which means “From Cyprus” as copper was abundant on the island and most of Roman copper supplies were mined there. In its pure, or “native” state, it’s a handsome reddish-orange metal. In fact, it’s one of only four metals on the periodic table that are not gray or silver – cesium, gold, and osmium being the others. It is relatively soft and ductile, and an excellent conductor of heat and electricity, which is why it’s literally everywhere. The electricity and data that allow you to read this were likely delivered by copper cables, through various other copper components, to your screen.
Copper use began in a period between the Neolithic (Stone Age) and Bronze age, in an era known as the Chalcolithic or Copper Age. Makes sense. It was during this period that the first weapons and tools were formed from metal, replacing some stone implements. Interestingly, two early applications of copper still exist today – ornamental metalwork, like statues and reliefs, and copper pipes. Some of the copper pipes inside the temples and tombs of ancient Egypt are still functional today, nearly seven thousand years later. The era lasted around a millennium, at which point bronze smelting was discovered beginning the bronze age, which we covered in our bronze primer. Large scale copper mining and smelting continued through the classical and medieval period, supporting bronze and brass production.
But what about copper? Was it doomed to be a supporting metal for the rest of history?
Not this element. Thanks to some neat chemical properties, it still enjoys great popularity. Pure copper exposed to air will form an layer of oxide, which protects the metal. Naturally it’s a brown-black color, but the presence of salt or vinegar instead leads to a lovely green patina known as verdigris. This corrosion resistance, in addition to the attractive color, has led to extensive architectural use. It is also popular in modern statuary, most notable the Statue of Liberty. It is also completely recyclable, without any degradation. It is estimated that over 80% of the copper ever mined is still in use.
And the most important property of copper is that you actually cannot live without the stuff. It does so many things inside our bodies, in fact, that I could probably write a whole article on those processes alone. One fun fact – horseshoe crabs have copper-based blood, which makes it blue. This helps them get in to the best prep schools, I’m sure.
Here at Progressive Bronze, we treat copper much like it’s bronze and brass brothers. It is rarer to see, but it take a polish very nicely, and makes an attractive plate, handle, knocker, lamp, etc.
If you have something copper that needs a polish or repair, send us an email.