Ummm.. what is this, came out of my scalp

So I washed my hair last night so I know my hair is clean I sleep with a bonnet on when I wash my hair cuz curly hair and frizz control I was scratching my head and I felt this bump so I go to examine it I scratched again and boom this falls out. Now the spot it came out of is hella sensitive.

I’m like assuming it’s a pimple of some sort just don’t know what because it was hard like calcified maybe??? I crushed it with my fingers and...

It’s like the texture of chalk