Today I was cogitating on rare, investment grade noble metals. So many times I've heard how rare gold is but is it really rare, especially in comparison to other rare earth metals? I thought so. So then I began doing some research on what is the rarest metal on earth. What I learned is that the rarest metal on earth is also the densest naturally occurring element on the planet also. This noble metal has a name. It's called Osmium. "Osmium is the least abundant stable element in Earth's crust with an average mass fraction of 50 parts per trillion in the continental crust." http://en.wikipedia.org/wiki/Osmium Gold, by comparison, is very abundant. Noble metals are rare metals. Gold, platinum, palladium, and rhodium are considered investment metals because they are noble metals. So when is the rarest of the noble metals, Osmium, going to finally be considered an investment metal? Well, for some, apparently it already is. There may come a day when we see other noble metals like Osmium finally have a trading price set daily for it, like gold and platinum do. Osmium, if it can be found for purchase, is typically sold in powder form. For a laboratory or refinery to produce ingots of pure Osmium is not an easy accomplishment at all from what I've been reading....but it can be done and the ingots are not toxic if handled responsibly. Only the most exclusive jewelry designers have ever worked with Osmium because it is so hard, dense, and can be toxic if not refined properly. I found a research / laboratory and industrial provider that sells small, various purity bars of Osmium: http://www.americanelements.com/osmbbr.html I have no relation or relationship whatsoever with this firm. Through my research on Osmium, I found them. I also requested a quote for a 1 oz bar of Osmium. At under USD $2,000 for 99.9% pure Osmium, it seems like a great price considering how much more rare it is in comparison to gold and platinum. Osmium ingot .