Not sure how it got there, but theres a weird spot on my iPhone Leather case. Any idea how to clean it?

I don't want to get it darker. I've tried just using some water, I could try soap, but I had that destroy a leather case in the past.Looks like a water stain. You might have some luck with mink oil but, it will darken the leather quite a bit and it may not hide the stain completely..