On the same subject, here are some thoughts from the venerable Doug Casey, who I've been following for decades.

http://www.kitco.com/news/video/show/On-The-Spot/796/2014-10-09/Fed-Can-Cause-Gold-Bubble-Super-Bubble-In-Mining-Stocks---Doug-Casey

Note - "Fed can cause gold bubble." ...Casey's looking for a "super bubble."

We've had a "bubble economy" through the last few Fed chairmen. We've gone from one bubble to another, and I'm thinking it's time for hard assests to be revisited, given the last real bubble in this area ended circa 1979-1980.

History also shows that hard assets have boom times 2 or 3 times per century. Well, it's been nearly 35 years, so...