McDonalds restaurants in Romania are superior to McDonalds in the U.S.A. The food is better, the service is better, they ask which Happy Meal toy your child wants, and… the tables are made out of beautiful SOLID GRANITE!
If it weren’t for “Super Size Me,” these tables would be enough to make any geologist eat at McDonalds every day. I didn’t eat there every day, but occasionally I would be there with students, and I would be sure to point out the granite tables. I would point out the potassium feldspar, quartz, amphiboles, and accessory minerals. I would show them the zoning in the feldspar crystals, and tell them that each mineral grain had a story to tell. I’d also point out that the table was probably somewhat radioactive, but at a level low enough that they really didn’t have to worry about it.
Earth Magazine has an article on this same topic: Granite Countertops: NOT Silent Killers.
Granite does contain elevated levels of uranium and thorium, and it releases tiny amounts of radioactive radon gas, which is the second leading cause of lung cancer after tobacco. But the radiation emitted by granite is generally at a level well within safety limits, and it is good to test your home for radon whether or not you have granite in the kitchen, as naturally-occuring radon seeping up from the ground is a greater risk than granite countertops. I wouldn’t recommend sleeping on a granite slab in an enclosed box every night for twenty years, but you are far more likely to die from the Big Macs and fries that are served on the granite table than from the radiation that table emits.
Grace and Peace
4 thoughts on “Granite tables and countertops”
I was with Kevin when he took this picture. I have never seen anyone more excited over a table!
Proud of my little brother,
Granite contains relatively high amounts of potassium, as compared to many other types of rocks like limestones, because of all the potassium feldspar in granite. Potassium 40, occuring naturally with the rest of the potassium, decays radioactively and produces as much as 95% of the radioactivity coming from granitic rocks, as measured in Total Counts by a scintillometer (or Geiger counter). A good article about this can be found here.
If granites were dangerous, then people would need to avoid places like the Sierra Nevada mountains of California – and many other mountains in the world — and, no need to do that! Which is a good thing, in my opinion. :)
Thanks for the reminder on potassium-40, which I should have mentioned.