Mystery components? What are these?

[sourcedog]

So, quite some time ago I got an assorted collection of basic components cheaply on ebay (you have to start somewhere, right?) and basically, it's what I've expected it to be. But there was one bag in there with components I've never seen before: http://abload.de/img/20140802_192308shuif.jpg

What could that be? My interest is piqued quite a bit.

They seem to be some kind of diode. At least, if I use my multimeter the right way, that is If that's the case, do they have a special usage case?

[PA0PBZ]

I'd say zener diodes, looking at the different numbers on them which look like voltages a lot.

[sourcedog]

Alright, that seems to be case. I grabbed a random one out of the bag (one with 6.8 marked on it) and it has absolutely no conductivity in reverse and about several Megaohms in the other direction (forgot how much exactly). When turning my multimeter to diode test, it shows 0.68 Volts. Guess the weird package and the fact I don't understand zeners fully, yet, threw me off.

Thanks for the hint