When I remove the SD Card that was formatted by my Galaxy S3 from it and put it in a MacBook, fdisk shows its sole partition as having partition ID 0C, indicating that it is a Fat32 LBA partition. However, OSX is unable to mount it, and Ubuntu appears to be mounting it as an exFAT partition.
What is the filesystem used on this partition? Could a discrepancy between the partition ID and the filesystem used on the partition be preventing OSX from mounting the partition?
The reason is, at least with Samsung devices and cards larger than 32GB, Samsung or Android formats the card with the exFAT file system, but incorrectly identifies the partition type as "FAT32 (LBA)", or partition type "c" or "0c" in the card's partition table.
If you format the card with exFAT using Windows or the Android partitioning app Aparted, it will correctly declare the partition type as 7 or "07" for "exFAT" (HPFS/NTFS/exFAT) in the microSD partition table.
I have struggled with this same problem, and just confirmed the above information by formating a completely blank, unpartitioned 200GB microSD card on a Samsung Galaxy Note 3 with Android 4.4.2, and in Windows, and using Aparted on Android.
If you are trying to recover data from a card that was formatted with exFAT, but whose partition is incorrectly identified as "FAT32 (LBA)" or "c" or "0c" in the partition table, I believe you will need to force the recovery app (e.g. Testdisk) to identify it as HPFS/NTFS/exFAT or "07".
I formatted a 1GB micro SD card in my SGS 3 (Android 4.3) then checked it in Windows 8.1 on a PC. The Properties dialog says it is FAT. (also the PC can read the content without any problems)
I also formatted it to exFAT on the PC and put it in the phone. It could read and write to it. On the other hand, a NTFS card was reported as unsupported.
More info:
According to this forum post: [Q] What filesystem is used for SD cards on the S3? :
Anything 32GB and under will be FAT32. 64GB will be extFAT.
For your card the best bet is to try mounting it in Linux (supports the most file systems, note: for exFAT an additional package might need to be installed). If it works, check the used filesystem, like with cat /proc/mounts.
