by Michael Murray
Sat, 3 Feb 2007
I've been hunting meteorites with supermagnets for a little over four years now. As I am sure everyone knows, when you drag a magnet you pick up all sorts of stuff including a lot of magnetite, at least here where I hunt you do. If you're interested in this type of hunting, here is how I deal with all the metal junk, the magnetite and the small stones.
I clean the magnet off into a gold pan. I then screen it all through a very fine screen to remove the magnetite particles. I dump the stuff left in the screen back into the pan and I add water with a drop of dish soap and wash. I use a swirl and dump motion to get rid of the dirt and trash only. I usually repeat this process with clean water at least a couple time until the water remains fairly clean. I pass a magnet (not a supermagnet) over the stones at about 1/2 to 3/4" above and pull out all the bits of metal and examine them somewhat closely before getting rid of those pieces. Don't want to inadvertently pick up a suspect stone and throw it out with the scrap.
Now to have a look at all the little stones left. I will leave just a small amount of water in the pan with the material so that I can still swirl the contents if I want. Then I take it outside in the sunlight and take my first look. If I don't see anything right away that gets my attention, I'll drain all the water off and let the contents of the pan dry completely. Usually I just leave it sit for a day or so. So when it is dry, I take the pan in and put it under my mscope and go through the contents with close scrutiny. Sometimes, I have even done this when the contents were still wet. Anyway, if I see something that sticks out as unusual and interesting, I pick it out and take a closer look.
One quick way to separate the magnetic stones is to place a strong magnet on the underside of the pan then swirl the rocks for a bit over the area where the magnet is located. All the strongly magnetic rocks will collect in one spot. Then just take the magnet over them from above and lift them out. This lets you get down to taking a look at the magnetic rocks in a hurry if you so wish.
I realize none of this is very scientific. It's a hobby for me and gives me something relaxing to do in my spare time and I get exercise from the walks. The thrill in it all comes when I actually have something of extraterrestrial origin to look at and hold in my hand. Then I also get a lot more enjoyment out of studying the suspect rock to find out what it could be.
After you have been through about a five gallon bucket full of these pea-size rocks you have a real good feel for what is a suspect meteorite or is actually a terrestrial stone (I guess you could call some of these meteorwrongs). I have studied the many, many, many little "meteorwrongs" to a fairthywell. To have a good meteorwrong to study can be a good learning tool. I have a collection of small rocks that I keep and add to on occasion that are the best wrongs that I have found. I look at them every once in a while under magnification to refresh my memory on a particular feature or whatever. I like to refer to them as "intrinsically incorrect" compared to meteorites. Some are actually very interesting. How about a rock that looks like chrome when you grind off a small spot and polish it a little but it is totally not magnetic. You can't make it leave a streak, it never rusts and is very hard. I have not found but one piece of whatever it is and am glad to have that one to study even though it is not a meteorite. Believe me, I have researched this one and although I have my suspicions about it being Hematite, I still am not positive about it.
My style of hunting takes a lot of patience but has proved that Dr. H. H. Nininger was correct in this respect. There are a lot more meteorites of the 3/4" or smaller than most people might suspect. I have even found multiple pieces of the same fall doing this type of hunting in road gravels. Twice actually. Four pieces from one fall, two from another.
I have one hang-up however, I might talk myself into grinding a small window into an iron but I don't think I could force myself to cut or break a suspect stone - no matter the size. Especially improbable if I had solid evidence to support my thinking that it was actually a meteorite. To me the whole stone is far more of a beauty, a wonder and marvel than bits and pieces. I know that's weird and I probably should get over it.
Again, none of this is scientific I know, but if anyone is thinking about hunting with a magnet, hopefully some of this information will help you figure out a good process for dealing with what you pick up. Good luck hunting and don't loose your patience. Don't let your supermagnet get too close to your vehicle. If you stick it to a painted part of the vehicle, you could really damage the paint before you get it back off. Here is another tip...Don't use a ring type fluorescent magnifier lamp to study the stuff in your pan. The light intensity/reflected light, will cause you problems with your eyes, especially when there is water in the pan. A zoom, stereo microscope is far better to use for this reason.
Michael Murray nom de plume - Rockbiter