Electrum @ Reference with Hugh Scott Douglas

Western Anatolian electrum, then as now, has a gold content of 70 to 90 percent,while these coins have a gold content of 50 to 60 percent, with most of those that have been analyzed consisting of around 54 percent gold.This indicates that the Lydians added these metals to electrum. Silver was less expensive, as was copper, and it was likely that the small amount of copper that was added was done so to improve the coins’ color and hardness. Though some scholars disagree, the evidence, though not conclusive, suggests that the Lydians already possessed the technology to refine pure gold and silver and that if they wanted they could have produced pure gold coins, as they did shortly later during the rule of Kroisos (Croesus).