Snot Rock
A Snot Rock is a rock of mucus located in either the mouth or the throat. It is usually formed overnight when sitting mucus begins to harden. It is very disgusting and I myself have only witnessed it one time.
So I woke up this morning and as I'm about to get in the shower, I feel the need to cough. After I cough I feel a lump in my mouth and so I spit it out and a Snot Rock comes flying out.
Snot Rocks
This is where from being in a dusty area, you form small rocks in your nose from the collected dust. They look similar to popping rocks.
Bloke 1: Man this stupid dust in sydney, given me snot rocks.
Rock snot
when your boogers are so dry and hard it is as if you have rocks for snot. Usually discovered upon waking up in the morning, especially in the winter.
I tried blowing my nose when I woke up this morning but I had rock snot and nothing budged.