Grab a jetpack, and just start searching mountains. If you see a cave in a mountain, dive it. If you get access to a mining laser, then an easy way if you HAVE to get some apatite now, is to set it to scatter, and fire a couple shots into a mountain.
You don't need any appetite though until you can generate something like ~4 stacks of copper, because the costs of setting up a farm are quite a bit. --- "What kind of dumbass runs from the cops and returns to the scene of the crime a minute later" -asked of a forumite
It's sort of hard to find, but it comes in massive veins when you do find it.
I would suggest just wandering around and looking for surface apatite in shallow caves and the sides of hills-- it's pretty distinct when it appears. If you have the XP for enchants, If you have a Fortune pick, I think apatite is one of the ores it works with. --- I have a blog! Warcraft and other gamer musings. http://oilstainedlibram.wordpress.com/
It does work with fortune... but trust me, you'll get more then enough without it.
Wiith it... you'll not want to mine out the entire vein because you'll have too much bagspace taken up. --- "What kind of dumbass runs from the cops and returns to the scene of the crime a minute later" -asked of a forumite
I got 7 and a half stacks of the stuff from one vein without a Fortune pick. And there was another vein like 30 blocks in the other direction to give me another 6 stacks. And that was just the north face of the mountain. The south face had another 3 veins that I went back and mined later for an additional 14 stacks. I have enough for like 40 farms lol. --- http://www.reverbnation.com/the570killa