Stone-trolls

Stone-trolls are huge trolls, slightly bigger then Hill-trolls, who turn to stone in direct sunlight. In The Hobbit, Bilbo and company met a group of Stone Trolls known as Tom, Bert, and William. Gandalf defeated these trolls by tricking them into staying in the clearing until the sun came out, when they turned to stone.

Habits
Stone-trolls tend to be dumb and ill-tempered. Almost all Stone-trolls have first names, and a few (like William Huggins) had last names. Stone Trolls eat things such as: wild fowl, wild pigs/boars, Dwarves, Hobbits, and fish (if they could actually catch them). They hunted simply by chasing or ambushing the animals, then hitting them with a weapons, such as an axe or a wooden club.

Shelter
Stone-trolls commonly lived in caves or large borrows that went many yards underground. They slept on beds made of grasses and leaves or animal hides.

War
Stone-trolls participated in the War of Wrath, but they are not known to fight in any other wars. In the War of Wrath, they were used as beasts of burden and as shock troops, using giant axes and clubs to frighten their foes.

Confusion
It is hard to say of what the term "Stone-troll" actually means because generally almost all trolls kick the bucket when hit by sunlight. One possible meaning (as used in the book version of Fellowship of the Ring) is "any troll that has been turned to stone by the sun". Another possible meaning is that it is intended as a synonym for Olog-hai since these do not ever turn to stone.