Parition disapeared after deleting Linux
If I'm understanding you correctly, you are trying to format a linux partition from your OS X diskutil app. Far better would be to access it via an external linux boot device, either USB or DVD. Since what you do to that partition as far as a reinstall of linux should (fingers crossed) only mess with the linux partition, your ability to later on reboot into OS X should be (fingers crossed) fine. As I am finding out myself, deleting partitions within one or the other systems may well befoul everything. But reinstalling to one of them should have less risk involved. BACKING UP the OS X partition first would be a stellar idea.

I say this as someone running a MacBook late-2011 15" with Mint Linux as first partition and MacOS as second.