All told, humans have mined some 120,000 to 140,000 metric tons (1 metric ton = 1000 kilogram) of gold from the earth since the start of recorded history. Around 20-25% (30,000 metric tons) of this gold is hoarded by central banks, according to Taiba.ae. “The rest is privately owned jewelry (70,000-80,000 metric tons) and bullion (20,000 metric tons),” Taiba writes. “In other words, most of the world’s gold is in private hands. The amount of gold that is mined per year is comparatively stable at just above 2% of the worlds above ground gold (around 2,600 metric tons per year).”
That means there’s a worldwide supply of at least 3.8 billion ounces of gold in 2011. At today’s price of $1,369 per ounce, there’s some $4.3 trillion in gold trading on markets, locked away in vaults or being kept or worn as jewelry.