@mainiac
... What. I don't know what you're refuting, or if you're really refuting anything? That just read like a stream of disconnected economics claims. There's not an endless supply of any investor, and I'm not claiming there is. I'm claiming that Bitcoins have a self-perpetuating psychological attraction that may be enough to keep its value going for a few years, based on the idea that they can function as a get-rich-quick investment, which is pretty characteristic of any bubble. I don't know, however, whether the bubble will burst or not before it stabilizes into a standard fixture of the Internet for some time (see: Youtube). I thought the bubble burst with the whole China thing, but it's been recovering fairly steadily since, so I dunno. But, again, I really don't know what I'm trying to respond to, so clarification is all I can do here.
@kaijyuu
Natural diamonds, however, remain rare. My point is that when people go out to buy jewelry, they often are looking for expensive jewelry because they want to demonstrate that they have and are willing to spend the wealth for some expensive jewelry. If diamond prices fell, they'd buy something else, but because the price tag is often the point, sellers can point out the rarity of natural gemstones as a reason for keeping a high price, even though it's fairly arbitrary. So now you have to buy a natural diamond to show off your wealth or commitment or whatever, and since that's one of the major reasons people buy diamonds in the first place, it's not worth stocking the cheaper ones. Which is great for everybody except the people who just like how diamonds look or who need them for something more practical but can't afford the industrial quantities you need for lab-grown ones to be cost-effective.
You're right about the producers manipulating the market, I'm not disputing that, I'm just saying that I think there's an analogue here between the value an item gains soley from being ascribed value in both diamonds and in cryptocurrency.