Recovery Mode is taking too long to erase my USB stick I had some problems with my USB stick so I wanted to erase it via Disk Utility but a "Operation failed" message appeared.

So, I am currently erasing it via Recovery Mode.

However, it is taking too long and it's stuck in "Mounting disk" message. 

Any solution? What happens if I shut down my computer and just use another USB stick?

Please help ASAP. 

Thanks.
Here's a trick that I've used before.  On the Disk Utility sidebar, if you select the storage device, not the partition, you have the option to completely erase the disk and rebuild the partition table.  It looks like this:



Compare this to what you see if you just try to erase and reformat the partition:


Notice that the "Scheme" option is missing.  If you use this option (which I believe is what you're trying to do), then it's trying to work with the existing partitioning and metadata, which has the potential to cause problems like what you're seeing.