The Bronze Age
Contributed by Riomacleod
The next step out of the Copper Age was the Bronze Age. Its defining achievement was the invention of bronze, and the use of it in weaponry. Bronze is an alloy of copper and tin, and has a darker, reddish hue, that can be polished to a very beautiful sheen. The Chinese added lead to their bronze, replacing some of the tin, which gave the bronze a gray sheen, unique to that land.
The biggest advantage of bronze was that it could be cast into the shapes needed. In fact, swords, axes and arrowheads were all made of cast bronze. This was generally done by making a reverse mold of the desired shape made of stone or clay, and pouring the mix of molten tin and copper into the molds. When the weapons hardened, they had their basic shape, and could then have an edge ground onto them. Bronze was the first metal that allowed the creation of actual swords, though most of these were in form and function much like long knives, we can refer to them as what we know as short-swords.
Bronze was used because of the ease at which copper and tin are extracted from the earth. Originally, it's assumed that raw copper metal was taken, since it forms sulfides in the ground, there was a significant amount of copper that was in its pure metal form. As cultures became more advanced, they were able to begin smelting copper from ores. This required a furnace of charcoal, and for a long time ores of copper were the only weapon-grade ores that were smelted in this way. That is, until 1200 BC, when the Greeks began using iron. Iron Ore is much more common and easier to mine than copper or tin, and once furnaces got hot enough to smelt Iron (around 1,000 BC) they began to mass-produce the superior iron weapons.
Bronze, however, is still used today in art and architecture, anywhere where we want corrosion-resistant, beautiful ornimentation.