Rarest material?

Does anyone know what the rarest material is in existence? I remember hearing somehwere that it was some kinds of mushrooms (Maybe certain truffles?) or food. I would think it would be some strange metal from a fallen meteorite or even the naturally occuring alloy of gold and I think it was with tin or copper(?) found in some mountain in South America.
-Morgan:confused:

My guess would be antimatter. It does occur, but it’s so incredibly rare that even a hundredth of a milligram would be n insane find.

Over at CERN, they recently put together 50,000 atoms of antihydrogen. That’s the most anyone has ever been able to obtain, yet it still masses less than a quarter of the weight of a single molecule of human hemoglobin.
-Damn you Netbrian ! :wink:

If only human stupidity were as rare…

Antimatter was what popped into my head when I saw the thread title. I heard some scientist on the radio recently saying that there had been some huge breakthrough in antimatter handling technology or something. He noted in passing that all of the antimatter ever produced wouldn’t make up an anti-paperclip.

I don’t think that anti-matter is even as rare as some of the very heavy isotopes that last for only billionths of a second. How about the top-quark?

You need to put some qualifiers here. When you mention somthing like truffles it sounds like you have a different idea of what “material” is from the rest of us.

When I was a kid, the Guiness book listed Californium 252 as the rarest of rare. Its an isotope of a synthetic element. I doubt it was stable. Since it is synthetic, it is undoubtedly a good deal rarer than anti-hydrogen, which occurs naturally, not that we can get at it.

Right you are. Nothing above Uranium is stable. Ca[sup]252[/sup] has a half-life of 2.6 years. I imagine that the ridiculously hard-to-make stuff is effectively nonexistant. For instance, if humans are the only intelligent beings in the Universe, then I would guess that there are currently 0 atoms of Meitnerium-226, which has a half-life of 3.4 milliseconds, in the Universe.

Neutronium.

That’s not necessarily true. Scientists have speculated a stable island of super heavy elements.

I’m not a chemist, but there must be some class of big molecule which are so complex that, like snowflakes, no two in the universe are alike? Perhaps if you take a human DNA and make a tiny change so it’s slightly different from all the other DNAs from that person…

Really? Neat. Any handy links for the curious?

Well that’s funny - I thought bismuth was the highest-numbered known element which had stable isotopes. What exactly are the stable isotopes of elements 84 through 91?

Well, if you consider intelligence to be the polar opposite of stupidity, and stupidity is found en masse everywhere in the world, then perhaps the single rarest material is intelligence. :wink:

Just google “superheavy island.”

Scientific American did a good story on it called, “Voyage to Superheavy Island” a while back. There may still be archived copies of it somewhere on-line.

Googling for “Island of stability” might give you some good results too.

Link, for instance, this one

Sorry for the continued hijack.

I’m not sure if you were referring to my post when I said that “Nothing above Uranium is stable”. Note that even if nothing above Bismuth is stable, my statement is still true, so I covered my bases. :wink: But I can still clarify what I meant. It depends on what you mean by stable, of course. Uranium-238 (element 92) has a half-life which is one-third the age of the Universe, and it occurs naturally. So yeah, while it’s not stable per se, it seems strange to call something you can find all over the place unstable. In the context of what I was talking about, I was making the point that you won’t find anything above Uranium lying around.

Now, it is thought that even protons have a half-life of 10[sup]90[/sup] years or so, so in a sense, no chemical element is stable.

As for islands of stability, this is true too. I should say that there are no known stable elements above Bismuth. And there are no naturally occurring elements above Uranium.

I thought Iron was the most stable element (don’t remember which Isotope).

Brian

Unobtainium.

Seriously, though, since you asked for the rarest material “in existence” rather than “on Earth”, that complicates things a bit. I’m sure that somewhere in the universe there’s a deep dark cave containing just one atom/molecule of some freaky substance we’ve never heard of and never will.

I suppose it would depend on your definition of “substance,” as the various answers given already would make clear.

Urban Ranger, neutronium is quite common, just not nearby. The core of the Crab Nebula contains a pulsar largely made up of several octillion tons of the stuff. Of course, to access it, you’d have to travel 3500 light years, then protect yourself from an intense radiation field in the star’s accretion disk, and then invent something that can stand up to several million gravities (the “surface gravity” of the star) and whatever temperature the star is at, and excavate through degenerate matter, to get at the neutronium.

IIRC, there are stars with technetium in their spectrum; since it has no stable isotopes, technetium does not exist on earth.

Of naturally occurrig elements, plutonium would have to be the rarest, since it only exists in miniscule quantities where a U-238 atom has absorbed a slow neutron and suffered beta decay to Pu-239, an extremely rare but not impossible occurrence. There’s probably several orders of magnitude more manmade plutonium than naturally occurring plutionium on Earth.