ID of white spots on the rock. First and last picture is in tank on rock. second and third pictures are some of the spots I scraped off a snail shell. They have grown over the last few months and don't seem to bother anything. They have a hard outer shell and are almost like small round dots. they don't seem to be live creatures but maybe something like coralline alga however it is white.
It is spread throughout the rock
It is spread throughout the rock