Manna from the heavens

by Kathryn Graham
The Metropolitan

If a bunch of hundred dollar bills were on the ground would you stop to pick them up?

Meteorites are like cash from above. Although most meteorite finds won't make one rich, finding one could pay for a whole semester at Metro, including books. All that is needed is a little knowledge of what to look for and a lot of luck.

Photo courtesy of The Denver Gem and Mineral Show
The 37th Annual Denver Gem and Mineral Show drew thousands of geology enthusiasts and the curious alike Sept. 17 - 19.

Many pass meteorites without realizing it, thinking they are just ordinary rocks. That's like finding money on the ground without stopping to pick it up.

If a rock has a brown or black fusion crust and is unusually heavy it's probably a meteorite. Another way to evaluate a possible meteorite is to see if it's magnetic. Hold a magnet up to the rock in question and see if it sticks.

"Use a very strong magnet; the stronger the better," said Anne Black, a local meteorite collector, dealer and enthusiast.

Black is also co-author of the reference book "Meteorites From A to Z."

Although there are many different types of meteorites, most have iron in them; even the stony meteorites contain some iron fragments that will stick to the magnet, indicating its authenticity.

A good magnet for testing possible meteorites can be purchased at a hardware store. The kind carpenters use to pick up nails is a good kind to buy. About 90 percent of meteorites are stony and about 90 percent of those stony meteorites contain iron, making the magnet test a method that will work with most meteorites, said Black.

You can also take a piece of sandpaper and polish the corner of the rock to look to see if there is iron in it.

"Another way to know is if a rock looks like it doesn't belong there," Black said.

This month, hundreds of gem and meteorite dealers from around the world, including Black, gathered at the annual Denver Gem and Mineral Show. Volunteers from local clubs and societies organize the show each year. The show began organizing officially in the 1960s.

People, mostly "rock hounds," from all over the world, come for the purpose of buying, selling and trading. Dealers set up booths displaying their precious gems and stones but they're not always in the rough. Some dealers have creatively turned these gems, fossils and stones into beautiful jewelry, vases, sculptures, furniture and much more. You don't have to be a rock hound to enjoy this show and many different meteorites can be found there.

The most sought-after meteorites are the Lunar and Martian-only one percent of meteorites found are either of these. Lunar and Martian meteorites typically don't have iron in them, making them harder to recognize and, because of their rarity, worth a lot more money. Magnet testing will not reveal their identities.

A piece of the Martian meteorite Dar Al Gani 489, weighing only 1.69 grams apiece-smaller than the size of a pinky nail-was selling for $1,150 at the Denver Gem and Mineral Show.

"All of us big-time dealers have a piece of this one," said Ron Ruschman, a gem and meteorite dealer from South Dakota

Not all dealers, however, aggressively seek to collect Lunar and Martian meteorites.

"I don't do Lunar and Martian meteorites because their price goes down each time they find another one," said Black.

Because iron rusts, most dealers and collectors prefer meteorites such as Gibeon, an African meteorite, and Sikhote-Alin, a Russian meteorite, both of which are rust-resistant due to their high nickel content. Although pieces of those are not cheap, they are reasonably priced when compared to the Lunar and Martian meteorite varieties.

The least expensive and largest recorded meteorite is the extremely rusty Nan tan, named after the town in China where it fell. The total weight of the original find was a little more than 9,000 kilograms.

"It's the cheapest because there is so much of it and it is not good looking. It's a pretty ugly one," said Zhouping Guo, a dealer from California who owns several pieces of Nan tan.

"It fell in 1516 and the locals thought it was a fire dragon that fell from the sky. That is what they recorded in history," Gou said. "It was later found in 1958 when China needed military iron during the Korean War and the country was on a campaign to find iron." Guo was one of the hundreds of dealers who set up a booth at this year's Denver Gem and Mineral Show.

Even though they fall all over the world, many meteorites are found right here in Colorado. "Colorado is the fourth highest state for finds," Ruschman said.

On the eastern plains, local farmers find meteorites by accidentally plowing them up. They fall wherever they want to, but western Colorado is a good place to look for meteorites because it's less looked-over; however, they are mixed with mountain rock making them harder to find, said Black.

Metal detectors are helpful when searching for meteorites, especially when there are massive amounts of other rocks present.