What is this black spot on my rubber?

[doppelmoral]

Basically the title, I noticed that there is a black spot on my rubber, in the main hitting area.

My racket case got very slightly wet yesterday from the rain, and I noticed it today. Could this be something like mold after just 1 day? Or just a marking of a ball?

The grip still seems fine, but I havent seen this before.

What do you think?

Cheers

 

[John_]

Could be dirt, try cleaning it with tt rubber cleaner, every company makes some sort of cleaner.

 

[mil]

dirt, can be cleaned, nothing unusual

 

[PaddyPolar]

It could be a mark from a table, the cornileu cheap tables leaves marks on balls, which can transfer to the rubber. This also explains why its in the hitting area.

 

[zeio]

Could be black ink from the brand on the ball.

 

[Tinykin]

Dirty, greasy finger mark