It’s marble. This is what you get with marble. Soak it in acetone and remove the chip. Then just lightly polish the edge, and wait for more inevitable chips to form the patina.

They didn't use epoxy, they used cheap polyester which is unable to withstand ultraviolet light degradation. Or too much catalyst so they wouldn't have to wait for set-up. Too much catalyst will cause yellowing also.

I've soaked a bowl off with acetone, so that should remove the chip. I'd decontaminate, color match some methacrylate, overfill, scrape, and polish. I'd look better than that and wouldn't yellow.

Not a chip repair (bisected sink clip slot fix), but you get the idea:

Thanks guys, how do I go about soaking in acetone with that angle? Desolve the resin so I can readhere the marble chip with something else? Thanks for any help. That repair looks pretty incredible

Tape some Saran wrap under the top. Place an acetone-soaked paper towel over the chip, then quickly bring the Saran Wrap over the paper towel and tape it down. Go to bed. It may be loose in the morning; may take another application.

Awesome, thanks Joseph! You happen to live in Virginia? Haha