The innovation of smelting and casting metals in the Bronze Age started to change the way that cultures developed and interacted with each other. Starting around 5,500 BCE, early smiths began to re-shape native metals of copper and gold, without the use of fire and by using tools and weapons. The heating of copper and its shaping with hammers began around 5,000 BCE. Melting and casting started around 4,000 BCE. Metallurgy had its dawn with the reduction of copper from its ore around 3,500 BCE. The first alloy, bronze came into use around 3,000 BCE.