The thing about mines, is that even though they are phased out, everyone can still see them. the phased out just makes it so they cannot be attacked.
Gravity mines are different from normal mines in that instead of damaging the enemy, they slow them down and disable their phase drives for a period of time (not sure how much exactly.) As a result, gravity mines arent used very often...in another post, I proposed that a way to make gravity mines more useable in the future could be to make them completely invisible, so the enemy couldnt see them until it was too late, and they were slowed for some time, allowing you to do what you wanted or something.
