what kind of rock is this???

[critter27]

What kind of rock(?) is this? I found it in my back yard in Central Wisconsin. It is a little over a foot long and about 6" high. It also has a diameter of 21 1/2". It weighs in at 38 pounds!! It is grayish in coloring and holds an earth magnet with no problems (no sliding). It looks smooth, but has a rougher surface, almost like a rougher sand paper. I took it to a local lapidary shop & the owner has no idea what it is, but he wanted to cut it open. I would like to try and identify it first.

 

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[High Plains Digger]

Interesting that it seems to have iron ore in it but is not brown. I say, surgery! As in biectemy.

 

[bradyboy]

not sure i understand this post - its a rock
no markings
I dont see anything remarkable about this stone
Brady

 

[High Plains Digger]

And to think I came to your defense once. Not that you needed it...............but it is a ROCK. I know, maybe a little on the boring side, but when a magnet sticks to it, that is something. I don't think I would have lugged that boring of a rock back home from the rock shop without taking him up on his offer to slice it. Just imagine if you had rare earth magnets built in to the bottoms of your shoes as you were walking around in your back yard. Clunk! "I'm stuck to a rock and can't get off". Imagine the humiliation of the 911 call: "A WHAT?? grabbed your foot?" And the EMTs standing around laughing. "We don't carry a crow-bar. Never needed one before...." Of course it is important that we know what this rock is so that his yard can be completely cleansed of these things before something bad happens. Now, come on bradyboy, give us a guess!

 

[stefen]

Many times called a "JUSTA" or "JAFR"

In layman terms it's "Just another rock"....

And sometimes, depending on how frustrated you are, then it becomes "Just Another F'ing Rock"...

 

[critter27]

OK , this might seem to be just a rock ,but what brought it to my attention was the weight ,compared to another rock the same size, this one was quite heavier,and when wet it turns a bluish color ,what got me even more was the local lapidary could not even guess to what it was (i mean come on he is a rock specialist)and seemed to eager to cut it open! I have iron ore rocks ,and they don't come close to size or color , I'm just looking to any guesses ? could it be another form of iron ore?

 

[creeper71]

OK , this might seem to be just a rock ,but what brought it to my attention was the weight ,compared to another rock the same size, this one was quite heavier,and when wet it turns a bluish color ,what got me even more was the local lapidary could not even guess to what it was (i mean come on he is a rock specialist)and seemed to eager to cut it open! I have iron ore rocks ,and they don't come close to size or color , I'm just looking to any guesses ? could it be another form of iron ore?

I know everyone in the entire world usually jumps to sayin this right away, but do you think it is a meterorrite?? I am asking cause lapidary wanted to slice it so he must think it is something to waste time an possible broken blade

 

[trixie charger]

I am a Rock Hound! We have plenty of rocks in this area that looks just like it!!! But, NONE sticks to a Magnet!!! and the weight is high for its size I also agree that, other than he liked to gamble, he wouldn't waste a cutter blade for nothing?

 

[Roland58]

Did you find it with your locator? If so, what indications did you get? If you go to the lapidary guy, be cautious. Is there a college with a decent earth sciences dept. anywhere close to you? They may be of help.

With this little amount of info, I could only guess that it falls within the 'GOK' family......."God Only Knows."

 

[critter27]

My house is built into a hill ,the hill has many rock landscaping, I was testing out my new detector,coming across allot of iron on some of these rocks. I came across this one ,and it gave out : iron, AL/ZN(zinc) and coins(witch to the manual is: silver coins, pre-1982 copper). the rocks must have been shipped in for doing all the landscaping from the previous owner of the house. I Will have to look to see if there is a college in the area. With the lapidary? he said he "thinks" it's just iron ore, but why was he willing to cut into it ? As for a meteorite I don't want to get ahead of myself, it doesn't have the "normal" charters (black , glossy, smooth, rust spots) ,unless I'm confused on that .

 

[Roland58]

Critter,
The lapidary's comment about the rock being simply "iron ore" is why I said be cautious. If it were iron ore, I would think it would have more of a reddish, rusty look to it, at least, that is what all the iron ore I have ever seen looks like. And, like you, I don't see that it has any of the characteristics of being a meteorite, but, I'm no expert on meteorites or any other rocks for that matter. What you do have is pretty unusual and interesting, for sure!
Please keep us posted on what you find out.....

Edit: a little added info......."Streaks"
Streak is what the rock leaves behind, like a crayon. Common ceramic tile, such as a bathroom or kitchen tile, has a smooth glazed slide and an unfinished dull side which is stuck to the wall when installed. Take the sample that you think is a meteorite and scratch it vigorously on the unglazed side of the tile. If it leaves a black gray streak the sample is almost certainly magnetite, and if it leaves a red-brown streak it is almost certainly hematite. A meteorite, unless it is very heavily weathered, will not leave a streak on the tile. If you don't have a ceramic tile, you can also use the inside of your toilet tank cover (the heavy rectangular lid on top of the tank).

 

[critter27]

I took your advice about scratching it on some ceramic. It left behind a blackish- gray streak on the first scratch. I did another scratch from a different area of the rock and it left behind a reddish- brown streak. Any more ideas?

 

[Roland58]

I took your advice about scratching it on some ceramic. It left behind a blackish- gray streak on the first scratch. I did another scratch from a different area of the rock and it left behind a reddish- brown streak. Any more ideas?

Only that it appears now that it is a rock of this planet, not a meteorite. Sorry, a meteorite of that size could have been worth a fortune, but, I'm afraid you're out of luck with this one. The streak of reddish brown would certainly be indicative of iron content and explain why the magnet sticks to it. Sounds like the lapidary cat was right.

 

[High Plains Digger]

I wonder if it has galena in it, resulting in the grey streak and the heavyness. Does the magnet stick everywhere? Or, could the little bits of black be magnetite? The galena would make the magnet less stickable, but there just isn't enough brown in the rock to seem like it has much iron. By the way, I think that many of the "iron ores" are not magnetic. I do not believe limonite is, for example.

 

[critter27]

OK, first I realy thank everyone for the help,next I took the magnet to every square inch of this rock and it sticks to it without any problem,also there were grey powdered shavings stuck to the magnet after I was done.

 

[critter27]

I'm doing some looking into this rock, one thought is it could be "Niagara Dolomite",and trying to get hold of a person in the "Earth science" field is difficult ,they don't like to return Email's

 

[High Plains Digger]

And what is in Niagra Dolomite that makes it have magnetic (or at least magnet attraction) properties?

Be careful just looking at pictures. As a kid I had the little book on rocks and minerals, and I went to Moonstone Bay looking for rocks that had a blue center with a whitish stone around it. That is what the picture showed, but not what moonstone looks like. For me, having grown up in the Mother Lode region of the Sierra Nevadas, you rock looks like fine grained granite. But that also would not necessarily contain anything that would attract a magnet.