Black swirly coil with white tip growing on live rock?

[BillyBay]

Can anyone help? I'm a new saltwater tank hobbiest, and we have had our tank running for about 2.5 months. I noticed a week ago that there were these black ,swirly, coil things growing off of my life rock? they seem to have a white tips at the end of them.i spotted about 5 of them so far, they don't seem to be harmful, can anyone help me identify?

 

[Flreefer]

Looks like it could possibly be a small Vermatid snail tube. Do you ever see a string of mucus coming out of it? If you do, it's a Vermatid, basically harmless.

 

[BillyBay]

Hey thanks for the reply I haven't seen anything come out of them, though I do think I have one of the ones you are talking about. These ones just look like a hard blackish brown coiled up shell but the white tip is rather soft looking. I tried to take a pic of the other one, srry if it's a bit blurry lol