I’d say autoimmune disease or maybe lupus
Thats strange, whats it feel like, did you pick at it. Cant be good, Id pixk it off and check it out
Looks like it might be a little piece of perlite or vermiculite to me.
I agree w/ @Jaysittinback I would pulled off. I seen something similar to it not long ago when here. It was a growth filled with tricones. I get rid of it it’s not going to hurt anything pulling it off
They need the laugh emoji too on this site lol
It’s natural Crack! Now that’s growing ZkillZ right there 
I took it off and it was kind of similar to chalk, maybe slightly harder. Broke it apart with my fingernail and it crumbled into a white powder.
Maybe it is some type of mineral deposit… there are two more on that plant but not on the other ones in the tent.
This is my second grow and they were on those plants also… was hoping someone was familiar with these.
Sounds like perlite I think @merlin44 got it.
Finding soil in a bud lately, I realized I could be more careful taking plants out to water too
Like I said… Natural Crack.
You’re in this hobby and you don’t know what Perlite is?