Newbie on Capacitor Values

[mindwave_21]

I have some capacitors that look like they are rated in Joules.  Is this possible?  I've only heard of caps in farads.  Anyways, the cap says (I hope this is a cap and I'm not being completely ignorant):
821J100V
I also have 222J, and a tantalum (I think) that says 1(mu)U.
Thanks!

[Xlrator]

That is the tolerance code. Print this for quick and easy reference.

http://www.csgnetwork.com/capmicainfo.html

[zener]

I think 82 is the value itself, 1 is the number of zero after the first two digit. Therefore it is 820pF. 100V is the voltage. The resulting value is in pF.