✅ SOLVED Hematite, Magnetite, or Slag

[Dougie Webb]

Happy Saturday y'all-

Found near creekbed outside of Stone Mountain, GA. Very heavily attracted to a magnet and extremely dense. I'm thinking it's magnetite, but I have a tendency to want to believe that slag isn't slag, so I'm putting it out here for this group of experts

Unfortunately did not have enough foresight to get good pictures of it before I put it in the rock tumbler for a day, but at least you'll have a frame of reference for what it looked like before. Thanks!

Before tumbler, obviously...



And a few views after...

 

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[TreasureCatto]

Try a streak test. Hematite should have a red to red-brown streak while Magnetite should give a black or dark grey streak.

 

[Dougie Webb]

Try a streak test. Hematite should have a red to red-brown streak while Magnetite should give a black or dark grey streak.
View attachment 1920686

OK. First, I showed the wrong picture of it "before." The correct one is below (color is a bit off...actual color was closer to the one below it. Second, it left a gray streak...but that rock looks nothing like pictures of magnetite that I've seen. Also attached below is another I found nearby that I have NOT put in the tumbler. Similar appearance, and the same grey streak.

Correct rock before tumbling



Similar rock found in same area. Heavy, strongly attracted to magnet, leaves a gray streak

 

[TreasureCatto]

The correct one is below.............it left a gray streak. Below is another I found nearby that I have NOT put in the tumbler. Similar appearance, and the same grey streak.

Correct rock before tumbling

View attachment 1920829

Similar rock found in same area. Heavy, strongly attracted to magnet, leaves a gray streak

View attachment 1920830

Now, IMO the "correct" rock looks like well weathered iron nodule by the bumpy look. Probably in a mix of one or two types of ore more or less ----> Slag

The 2nd rock looks the same ore as the first rock. Did you test that one as well? Also, where did you find these specimens?

 

[Dougie Webb]

They both left the same gray streak. I've read that iron slag tends not to leave a streak. Is that true? If it is, the only other thing it could be is magnetite. I did some more research and *have* found some pictures of magnetite that have a similar exterior to mine.

 

[Dougie Webb]

In terms of where I found it - geographically, outside of Atlanta. Both pieces were found on an old plot of land near what used to be roads or driveways --- which of course would lend credence to the "slag" argument

 

[TreasureCatto]

They both left the same gray streak. I've read that iron slag tends not to leave a streak. Is that true? If it is, the only other thing it could be is magnetite. I did some more research and *have* found some pictures of magnetite that have a similar exterior to mine.

You're right about slag "Tending" to not leave a streak because the majority of metal slag used and found in the U.S. is steel slag or crucible slag, and almost to about all steel shouldn't leave a streak. Weathered steel shouldn't either. Could've been from the oxides on it before the tumbler. My knowledge.

 

[GoldieLocks]

I go with the last image is some kind of slag.

 

[Red-Coat]

As per the picture I posted on your other thread in the 'Meteorite' forum, this is massive (non-granular) magnetite after a spell in a rock tumbler to remove the weathering and tarnish:

 

[Dougie Webb]

You're right about slag "Tending" to not leave a streak because the majority of metal slag used and found in the U.S. is steel slag or crucible slag, and almost to about all steel shouldn't leave a streak. Weathered steel shouldn't either. Could've been from the oxides on it before the tumbler. My knowledge.

The polished one easily left a gray streak as well...

 

[Dougie Webb]

The polished one easily left a gray streak as well...

Yeah, Red Coat, I came over here to mark as solved. I think the fact that it polished up to look almost identical to your rocks, and the fact that it still easily leaves a gray streak points to Magnetite.