I have 1 hen that her egg shell are like sand paper all over the whole egg not high bumps but like fine sand on it the egg has a normal shape. She is a pullet i think it's a Comet ot one of my RIR eggs I have 28 hens 43 weeks old and been doing this for a while now I think her 1st egg had a sandy shell.
Just used this link for another poster. This reference page explains the different egg defects. Alot of them are just common for new layers and are really nothing to worry about: