Laelia posted a guide to albredine rings on the DR message boards some time ago. With her permission, I now present her guide. I've taken the liberty of adding some reminders as well.
There's two kinds of albredine rings, albredine crystal rings and colorless/colored albredine rings.
Albredine Crystal Rings (updated)
They act something like a private gweth. To use them, you THINK TO [person] and they'll hear your message. This is useful as it will be a way for you to send private messages to your friend/ally/enemy. They have limited charges. I'm not sure if they crumble to dust, but I believe that most likely it just needs to be repaired.
These rings are pretty useful, and good for espionage work. *grin*
Albredine Color/Clear Rings
Everyone in the realm has their own color albredine ring. It's hard to say exactly how you get the color. The colors can be anywhere from whorled white to banded silver, obsidian black, etc. There's a lot of different colors.
These rings are ALWAYS on, so as long as you don't use up all the charges, you can hear everyone else that's using the same color ring as you. It is rare to get a ring that's the same color but not tuned on purpose to another group's, so you can be pretty sure that your thoughts are only going to your albredine ring group. As long as someone's wearing a ring tuned to your color, they can hear your group's thoughts.
As soon as you put on a COLORLESS (UNTUNED) albredine ring, it shifts to your personal color. The color of an albredine ring can be cleared by tapping it with a knife, and it will shift back to colorless. However, this will not untune it. (Once a ring is first attuned, the color cannot be changed by this method. It has to be attuned with the use of another colored ring)
To tune two rings together, one must be colorless and one must be colored. Tap the rings together and the colorless one should turn the color of the first. If you tap two rings together that are different colors you'll probably melt them both. *grin* You can have as many rings in a group as you like.
After that, when both people wear the rings, whenever one person TAPS their ring, they have about 10 seconds to send a "group" thought, that only goes to the people in their group, by thinking. These rings do not interfere with regular gweths, but it's possible to send out to the general gweths if you've got both those on and the albredine ring on. You'll know if you've sent to the albredine ring if you see your own message and a little "[group]" message in front of your message.
These rings do wear out after about 100 taps, but they can be recharged by someone with over 100 in MD. Just FOCUS on the ring and it'll be recharged. After that there's a possibility of it becoming untuned (and shifting to your color), after which you'll have to find the other person(s) wearing your color ring and have them retune it for you. There's also the chance that if you take your ring off and try to put it back on, you'll get the message "It just won't fit." If this happens, hold a metal weapon in your other hand and you'll be able to put it on. This is really really weird, but it works, heh.
These have a range about on par with the "chorus" channel (kyanite, sjatmal, and lasmodi), so they go pretty far, about southish part of Riverhaven to the north part of Crossing. You'll know you're almost out of range if you hear "[group faintly]". It's also dependant on your concentration like gweths are, so you might get the message that you need more time to concentrate.
One last thing, don't use any languge that you wouldn't on the regular gweths, it's monitored the same.