Stone Trolls (Or."Gurlog") were the most common Torog breed. While they typically were only 8 to 10 feet tall, their numbers made them the most feared of the Troll varieties. In fact, most people that knew of, or wrote about, the Tereg knew of no other Trolls and necessarily referred to Stone Trolls.
As their name suggested, Stone Trolls turned entirely and irreversibly to stone when exposed to direct sunlight. It was likely that these futile, nasty beings were the original Trolls, as all of the other types were improvements in some direction or other. They were like Hill Trolls in habit, but if anything, they were worse. Quarrelsome and fratricidal in the extreme, greedy for both sustenance and useless (to them) riches, they spent a great deal of time hoarding piles of food and treasure, stealing it from each other if the opportunity arose, and boasting of their riches.