Are these marks on the burners or the grates?
Since nothing comes in contact with the burners, I'm not sure how scrape marks would develop there.
If the marks are on the grates, then they're most likely coming from the underside of your pots & pans.
Could you post a picture?

Sorry I mean the grates on top where the pans hit. I will post a pic when I figure out how to do it. But it's not coming off the pans because they are cast iron too. And after years of use, sliding my cast iron pots and pans around, there aren't any white marks on the bottom of them.

I have a mix of commercial pans with a couple of cast iron pans that I use on my CC rangetop. (I know, not a BS.). The tops of my grates aren't black and pretty like when new. Instead, they looked white-ish like they were scraped, not chipped. Basically, they look used. Is that what you mean? I thought that was normal.

So, I just looked at my Bluestar grates and I have the same marks.
I use All-Clad cookware so I just assumed the marks were a result of the stainless coming in contact with the grates.
But I don't find it to be a problem and attribute it to normal wear.
Also, I believe, that unlike your cookware, the grates are porcelain coated so that may be the difference.

Are you using propane gas?

Hi thanks all for your quick responses!
not using propane. We have natural gas. I called it "chipping" because I didnt know how to describe it but yes it's more like scraping. To be honest, it didnt bother me until BS jumped to replace them. I only showed it to the appliance guy to ask, out of curiosity, what it was. But once BS jumped at replacing them, I thought it meant that it was a problem. I know there used to be a problem with the grates but I'm pretty sure I read here that BS is having them made by a different company now and the new company makes them better. I'm not going to worry about it since others have the same scraping. Thanks!