I just received my "new" 300GB Intel SSD 320 Series but when I turned it arround the surface looked like it has been used or is refurbished, see:
Can anyone who also has a 320 Series SSD or maybe an Intel SSD in general tell if that look is normal?
I paid a good amound of money for it so I'd like to make sure it hasn't been used before.
This look is 100% normal. The underside of all Intel SSDs consists of a metal alloy that's smooth but not shiny (probably some form of aluminium). What you're seeing is the result of a metal sanding process to make the underside smooth, but it isn't lapped (thus not shiny). Nobody spends time staring at the underside of their SSDs.
I have numerous Intel SSDs -- specifically two X25-V, four X25-M, and two 320-series drives, and all their undersides look exactly like that. There's some variance in the style/method, but they're all buffed/sanded in a circular pattern like what you see.
If the drive does not have an indicator on the label that it's refurbished, then it's a new drive.
You'll know if it's a used drive if SMART Attribute 9 (Power On Hours) on the 320-series drive has a non-zero value. You cannot go off of the LBA read/write attributes in SMART because chances are you've already done some reads/writes to it, but out of the factory those values are also zero.
TL;DR -- you're worrying about nothing. :-)
You can use Intel's SSD Toolbox or any other utility out there that can read SMART data from a disk. Be aware that most utilities won't label the attributes correctly (e.g. some will claim Attribute 123 is "Snakes On The Platters" while on an SSD it might represent "Number Of Dogs"); these softwares are, simply put, incorrect/faulty (and that's partially because the SMART attribute numbers and their meaning, nor their data/value format, is part of the ATA standard; yes you read that right).
Hands down the best SMART analysis software out there is smartmontools, but on the Windows platform it only works on Windows 2000/XP.
Just today I found out that Intel's SSD Toolbox doesn't properly name some of the SMART attributes for the 320-series drives -- Attribute 9 is not one of those so you can read/rely on that data reliably. Intel really needs to update the utility to properly label the attributes for 320-series drives. Likewise, I have an https://sourceforge.net/apps/trac/smartmontools/ticket/168 open ticket with the smartmontools folks to add identification and proper decoding of attributes in smartmontools for the 320-series too.