http://craftblock.me/forum/thread-3006.html, this is your ban report, it says you warned before and was kicked multiple times. Also, I don't think our staff goes around banning people if they hit diamonds, the mods have x-ray as well, not to use it to find diamonds themselves, but to instead look at other players, if we see a player hit a lot of diamonds or gold in 5 minutes, we go look, turn on x-ray, and start to view the player, if we see that they're making a 3x3 thing hitting all kinds of things, we let them go, but not always, if we see someone digging straight down and then hitting diamonds/mining towards diamonds very often, then we warn them to turn x-ray off. The mods are trying to help the server, not destroy it, we do our best and call what is for the best. If you want to get unbanned, I suggest using the template in the ban appeal.
Though I disagree with Starguy's method, I will note that, being in the same boat as him, there was no effort to communicate with me by Sun who banned me. I was kicked with a notice, and when I signed back on asking if I had been kicked for xray, no response was given. Also, I had about a dozen fruitless mine paths nearby, and was performing under typical strip-mining protocol. No comment was made on that. Had any effort been made to communicate, I wouldn't have been sitting here for the last two hours waiting to be unbanned.