Is it still a good idea to invest in precious metals / stones?

With gold and silver at record prices, is it a bad idea to still invest in it now? If our economy shows signs of recovery over the next few years won't the price drop considerably?

Has anyone thought about investing in diamonds? Has the price of diamonds been inflated over the past few years like gold or are the prices more stable?

I don't see how you could invest in diamonds other then owning stocks or ETFs in diamond mines or technology companies that make synthetic industrial diamonds. DeBeers did a good job of fooling the public into believing diamonds are rare and valuable.

I thought I read a chart line not to long ago that showed the value of diamonds on the market has dropped over the last 10 years or so relative to gold and silver and even compared to inflation adjusted US currency.

Well, if that's true, then diamonds are not a wise investment. eBay has made it extremely easy for the layman to compare and value diamonds and I was hoping that diamonds weren't over inflated (other that the price fixing of course) and would possibly be a more secure investment than gold right now.