It is not radon that causes magnetism. Good grief.

Anyway, it is possible it will be magnetic. I noticed that my Tan brown (a dark tan brown) in my bathroom has magnetic spots accidentally when I set my ultrasonic toothbrush head on it (and it stuck!). But, it hasn't affected the ability of my toothbrush to charge. Magnets aren't damaging to your health. And, I don't think the counters are strong enough to wipe credit cards and definitely not cell phones or laptops.

On the issue of radon--if it has a lot of that, well then you may want to consider...but that isn't what gives it magnetic properties.

Where is Karen?

Meaning since it does have a high amount of radon, I should reconsider? I have three kiddos... Just want to make sure it's safe!

I don't know who Karen is, but if she knows this kind of stuff, I hope she finds this thread! :)

I'm here! And I love this kind of stuff. :)

So, we've already dispensed with the idea of radon causing magnetic properties, well done. In fact, I would go so far as to doubt anything uttered by someone who says that radon makes a rock magnetic.

Also, we need to separate two things. If a magnet sticks to something the thing it sticks to isn't magnetic, it just contains iron. In that regard, yes, Absolute Black and most rocks in the granite family contain iron-rich minerals that will weakly attract a magnet. In general darker rocks have more of these minerals than lighter rocks (again, this only applies to the granite family of rocks, i.e. igneous rocks). I wouldn't worry about health, cell phones or anything else.

Does the rock give off radon? Perhaps a tiny amount, but if you have any kind of normal ventilation in your house then it's likely a non-issue.

Ready for some geologic trivia?
Igneous rocks form from a liquid magma. The magma is a slushy mix of minerals (hot slush, naturally). The iron-rich minerals will align themselves with the magnetic North pole when the rock is liquid. Once the magma cools, the minerals are locked in place. These minerals tell us where the magnetic North pole was when the rock forms, which is called paleomagnetism. This is an incredibly useful tool. For example we can look at old rocks and tell where they were when they formed. This helps us understand how Earth's tectonic plates have moved all around the globe.

Paleomagnetism also revealed that Earth's magnetic pole alternates from being at the North Pole to being at the South Pole. By looking at basalt on the ocean floor (Absolute Black is basalt, by the way), we can see that sometimes the iron-rich minerals point north and sometimes they point south. We can tell exactly when the magnetic poles have flipped. The pole flips pretty often ("often" from a geologic point of view, that is).

I think the next great sci-fi disaster movie should deal with what happens when the magnetic pole flips again. Navigation goes haywire, Boy Scouts get lost, flocks of birds and bats fly around confused, airplanes fly upside down. And who knows what other terrible things might happen. Perhaps even random charges appear on your credit card ("It wasn't me who ordered those backsplash tiles, honey, it must have been the magnetic poles flipping!").

Well, I have wandered rather OT now, haven't I? Anyway, aside from that last paragraph, the rest of this post is true. :)

Magnetic properties come from iron and nickel in the stone.

You would have to go to a table of the nuclides and see if a radioactive iron or nickel has radon in its decay product path.

Here is a link that might be useful: Chart of Nuclides

southernmum, I would not worry about randon or magnetism.

I got curious so I took a magnet and there is no reaction on my White Diamond granite. But there is some with my steel gray. Interesting!

Radon is a gas that only comes from the radioactive decay of uranium or thorium, so iron and nickel won't give you radon. Plenty of granites have some uranium in them, so there is a grain of truth to the worry about radon from granite. And by this I mean granite by the literal geologist's name, not the generalized countertop name.

Aside from radon gas, rocks can also be radioactive, meaning some of the elements in the rock are undergoing radioactive decay. That happens all the time and that's how geologists date rocks. It's still not something I would worry about but it would be fun to walk around the stone yard with a Geiger counter. What an excellent way to scare off customers!

Great info., Karen! Since you know about this sort of thing, here goes another question: the granite I picked out for my island is a gorgeous slab of Winter Springs from Brazil. With all my research on granite this evening, I've discovered a lot of granite from Brazil does have higher radon/uranium content. Would this be a deal killer, or no big deal? (*Can you tell that I have to sign away on all my granite and quartz tomorrow?!) Many thanks!

Very interesting, Karin! Thanks for sharing your expertise!!!

Karin- I just wanted to say that my 7 year old son is obsessed- OBSESSED- with geology and I so often find new geology tidbits to share with him in your posts. So thanks for that! I can't wait to tell him about the trivia you posted up thread when he wakes up in the morning!

Good luck with your decisions, OP!

I'd be worried about buying anything from a salesman that told you that. Seems like he really does not know the product that he is selling. That's certainly a red flag about him and the company that he works for.

Hi again,

I posted a reply about Brazilian granite in the other thread SouthernMum started. I'll paste the answer here too.

Oh and Chilibeans, that is awesome! Makes me very happy to hear that. Your son will have a great time when he gets to take a geology class.

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Hi SouthernMum,

That's a good question. I tried to look up Winter Springs granite but didn't find it.

What color is it? Uranium is found in true granites which are light in color. So you can rule it out if it's darker.

Either way, I don't think it's a deal killer. You can find scary stories about radioactive granite online but it's not prevalent. I wish I had a definitive answer for you, but it varies with every rock so there's not much I can tell you in absolute terms.

I would definitely not say that granite from Brazil is categorically risky. Brazil is a big place with lots of different rocks. We'd really need more info about the specific rock, rather than a blanket statement.

That said, I'd be interested to see the link where it says that, because I've never heard that before. Also, post a photo of Winter Springs so we can see what it really is.

Hope that helps!
Karin

I'm fascinated. I look at my new countertop and wonder where it originated; when was it formed and how. Are there dinosaurs trapped in it? It does have an interesting piece in it that is light grey and pearlish and almost looks like a hologram. I don't know the name of this particular granite. I'm attaching a photo. Can you tell me anything about it? it looks alot lighter in the photo b/c it was a bright sunny day; it's much darker inside.