Maybe buy a new sink. Back in 1969, two buddies and I spent a night in my parent's 18' Coachman trailer, along with 3 really cute girls. One of the girls dropped a bottle of Southern Comfort and it hit the sink and did the exact same chip that you're asking about. My dad made me buy a new sink but he never found out that it was done by a girl. Parents just thought it was a crazy guys night. Almost 50 years ago and my parents are gone now, but when I read your post about a chipped sink, I had an instant flashback. Thanks.
Duane