[ElanoraBryght]

From what I'm reading in archives (largely wayback machine of Ebonlore) the ring had three stages -
First introduced, ring was tradable, usable from inventory
After a very short time (looks like just weeks) it became no drop, usable only when equipped.
After an unknown time frame (less than a year) it stopped being given as a reward for the Thex Mallet quest.

The ring remains rechargable, if the holder has the faction to do the quest.