I have some on my quartz..only my theory, but I think minute depth blade scratches that happened during fabrication. I hope to see a method to remove the discoloration.

Thanks Anne. I appreciate you sharing your theory. We will see what others say about their theories and cleaning methods.

Those may be metal marks. Try some Magic Eraser please.

Thanks Joseph. I will try the magic eraser.

Likely your chairs or belt buckle or button (metal).

Easier/cheaper & with less potential to damage your quartz than magic eraser: Just mix some baking soda with water. That will also get out other hard-to-remove stains from your quartz without damaging it. I have successfully removed turmeric, wine, and even slime stains from quartz with it (note to all parents: slime can stain your quartz so be careful letting your kids play with it on your counter).

You can buy this pre-mixed as well. I have Mrs. Meyers Baking Soda Cleanser on hand at my house. It also works on pots and pans, flooring (grout), stovetops, and our PU leather chairs - among others. I also used it to clean grease stains off of our pavers.

Thank you so much. I was going to go out to purchase a magic eraser as I do not have one. I just tried the baking soda paste and it removed all the marks. I am curious about these marks as I am posting for an elderly friend who does not wear belts. She has support workers that come in and they wear scrubs. Perhaps her children are coming with belts or buttons. Can anything else cause these marks? Thank you.

I was able to get the marks off the kitchen quartz counter top with the baking soda paste but not those on the bathroom quartz counter top. I will buy a magic eraser and give it a try. Thanks everyone.

Just be careful with the Magic Eraser as it is essentially sandpaper.

Try leaving the paste there for awhile. Sometimes it needs a bit of time to work. Metal marks come off right away with it, so whatever is on the bathroom counter might be something else.

Thanks everyone- will keep working on these marks.

I used "The Pink Stuff" and it did the job. BTW, I use it also on stainless, grout, car wheels, stove racks, on and on.

Thank you. Do you use it on stainless steel appliances?