Black on my cats ear

[Sperks11]

My cat has black on the tip of his ear. It's on his fur too...kind of looks like paint...however I don't know how he would have gotten near paint let alone have it on the tip of his ear only.
Also it was on his left ear a week ago and has now faded and this morning it has appeared on his right ear.
Anyone have any ideas what it could be and whether something similar has happened to their cats before? Should I be worried? I have a photo but unsure how/if I can upload photos
Thanks everyone

Dirty oil from under a car? Has happened to ours from time to time.

Oh thank god, I read that black on an ear tip could be signs of skin cancer but oil does seem very likely. Thank you. Has definitely stopped me worrying :-)

They are terrors arent they!

I know someone whose elderly cat did get cancer on his ear tips. White ears and he liked sunbathing.
Won't be that if it fades and then shifts to the other ear. One of ours used to come in green. No idea at all how he managed that!!

We had a white cat who regularly came home covered in oil. We also used to have to put sun cream on his ears. He was the most regal looking cat you could meet. So was less than impressed when we used the coloured ones on him!

If the black marks continue, become crusty or red raw, please take him to the vet as it could be skin cancer. I grew up with four cats who all had it. If you catch it early, vet can remove to stop it spreading or getting worst. It's more common on white ears.