How to fix messed-up MacBook disk partition table? I have broken the disk of my Mac doing partitions with gparted. Now, nothing boots (except pendrives) and the OS X Rescue Disk recognizes the disk as Virtual Whole Disk. Nothing works, repairing or partitioning the disk throws errors.

Is there a Linux utility to reformat the disk completely as I could reinstall Mac OS X? It is extremely urgent, I am extremely nervous because it is for work, and I really don't know what to do. I do not need to recover data, just reinstall.
Yes. Boot into the mac's recovery, and reinstall (or repair) the drive.