Gold has been used throughout history as money and has been a relative standard for currency equivalents specific to economic regions or countries, until recent times. Many European countries implemented gold standards in the latter part of the 19th century until these were temporarily suspended in the financial crises involving World War I. After World War II, the Bretton Woods system pegged the United States dollar to gold at a rate of US$35 per troy ounce. The system existed until the 1971 Nixon Shock, when the US unilaterally suspended the direct convertibility of the United States dollar to gold and made the transition to a fiat currency system. The last currency to be divorced from gold was the Swiss Franc in 2000.
Since 1919 the most common benchmark for the price of gold has been the London gold fixing, a twice-daily telephone meeting of representatives from five bullion-trading firms of the London bullion market. Furthermore, gold is traded continuously throughout the world based on the intra-day spot price, derived from over-the-counter gold-trading markets around the world (code “XAU”).
Article Source: en.wikipedia.org