From Goldmoney
Gold is primarily used as money. Its main price drivers are real interest rate expectations, long-dated energy prices (the most important cost drivers of mining and processing) and central bank policy. While there are industrial applications of gold in the field of dentistry and semiconductors, almost all of the gold used in industrial processes is later recycled. That means that the above ground stock of gold consists of almost all of the gold that has ever been mined. It is very stable and is growing at the rate of global mining output. Silver, platinum, and palladium on the other hand, are mostly used in industrial applications. Their above ground stock is a lot smaller than the gold stock because a large share of what has been mined over the years has been used. The prices of these metals are driven largely by industrial demand and supply and to a much lesser extent by monetary demand. In other words, gold prices are behaving like money while prices for other precious metals behave mostly like commodities and only to a much lesser extent like money.