This item no longer drops in game. Back in the day, when Kunark first came out, loot tables were initially very screwed up. Gem encrested rings were actually on the same loot table as forest loops, and dropped off of mountain giants in Frontier Mountains (where I got mine the first week of Kunark's existence). A couple weeks after the release of the game, the loot tables were fixed, and the gem encrested ring dropped no more. (It's rumored to now drop in Veeshan's Peak, but this has not been confirmed, and it certainly doesn't drop in Sebilis) The gem encrested ring was perhaps the worst of the loot table mixups, because it was, and still is, considered "god loot", simply because it has an awesome amount of AC for a ring, and a generous amount of STR. Definitely better than anything that should have been dropping off of level 30 mobs. On Tunare, they sell for around 20k (on the rare occasion someone decides to part with one for plat), but with its extreme scarcity, the market is almost non-existent for this item. I'm certainly never selling mine.
-Hssithaa