Contributed by
May 1, 2008
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What's worth more, poop or iron?

It depends on how old the poop is, and the iron is in the form of a meteorite. And what you mean by "worth", too.

At an auction in New York, two pieces of 130 million-year-old fossilized dinosaur poop sold for $960. These are called coprolites, and are actually rather cool. I've seen some before*, and if you can get past the idea that they came out of the butt of an animal -- even a dinosaur -- they're really interesting.

But at that same auction, a rare form of meteorite did not sell. I can guess why: the expected selling price was well over $2 million! I was curious when I read that, but then I saw the picture: it's not any old meteorite; it's a pallasite, a rare and extremely beautiful rock. They're stunning: greenish-yellow olivine crystals are embedded in an iron matrix like a webbing.

Pallasites are chunks of asteroids that got smashed apart in impacts -- but not just any asteroid. In this case, the asteroid must have been big enough to have moderate gravity. The iron and other heavier elements began to sink to the core of the asteroid, while lighter elements floated to the top in a process called differentiation. Pallasites either form at the core/mantle boundary, or form when the impact mixed material from the core and mantle. Either way, pallasites come from deep inside a shattered asteroid that was big enough to have planet-like features.

And on top of that, they are simply gorgeous.

And what we have here in this auction is a pallasite over a meter across. I'm not surprised they were expecting millions for it! I'd love to own some nice samples, but I simply can't afford them. They go for hundreds or even thousands of dollars for good ones the size of a credit card. Sigh.

Anyway, so while the meteorite is worth more than the dinosaur poopy, it didn't sell. So is it really worth more? Maybe not until it sells. This is like the old question, if a dinosaur poops in the woods, and no one was there to see it, does it fossilize?

Isn't that how it goes? I get my expressions mixed up sometimes.

I can't resist linking to Steven King's most famous line (as character Jordy Verrill) in Creepshow (NSFW language). I thought of approximately eighty bazillion puns to use in this post, but wisely refrained from using them. Except for the title. I caution people to keep it clean in the comments, though I imagine that's too much to ask. At least try to keep it reasonably clean, OK? :-)

Tip o' the coprolite scooper to Larry Klaes.

*Years ago I was summoned by an astronomer to talk with him about joining up on a big project. I sat in his office, and saw lots of little toys and things on his desk. Inside a little plastic case was a lump of rock, and I knew immediately what it was. "Is that a coprolite?" I asked him, and by the look on his face I could tell the position on the project was mine for the asking. Knowing your poop comes in handy sometimes.