Need guidance on sink replacement

Pulled the original equipment (20 years old) from our bathroom and found a gnarly yellow stain on the vanity top. I’m unsure what material it is.

Any way to clean this?

Our new faucet doesn’t fully cover the yellow spots.

Pulled the original equipment (20 years old) from our bathroom and found a gnarly yellow stain on the vanity top. I’m unsure what material it is.

Any way to clean this?

Our new faucet doesn’t fully cover the yellow spots.