Legends say that trolls turn to stone when they die. That is the reason why there are so many rocks in Norway.
....... Grandfather also noted that not all trolls turned to stone immediately when touched by the sun, especially if they were wearing thick clothes or only in the sun a short time like dashing from shadow to shadow. Sometimes it depended on their disposition. He wrote that ‘the meanest and the orneriest’ of trolls were in the greatest danger of being turned to stone. “The harder the heart the greater the danger.” and added “The softer the soul the safer the troll.” Of course he said there were always exceptions and he believed that some very nice and gentle trolls were turned to stone so that is the reason why trolls avoid direct sunlight as much as possible to this day. In a much later entry, when he had settled down, he wrote that he believed the good or gentle trolls were turned to stone because they ‘had a heavy heart’ for one reason or another. I do not know if this is true and I have never seen anything to prove it but if you read legends and myths the facts speak for themselves. I guess that means ‘light-hearted trolls’ could go anywhere. My own grandfather confirmed this by adding that a happy and carefree troll behaved as they wanted, where and when they wanted. They are all taught (he added) to avoid the sun because no one knew just how bad or sad one had to be to be turned to stone. Grandfather Bernt also wrote that as trolls got old and lazy their hearts grew heavy and they turned to stone from shear boredom. ‘Stone bored’ he called it.
(from the story Old Mart And The Fox)
.......Trolls turned to stone because of the nature of their hearts, and sometimes the sun or a church bell was the final catalyst. In reality, however, most trolls, like himself, avoided the sun because there were fewer people in it and they did not like the bright light in their eyes.
From the book "The Scandinavian TROLL, it's life and history"
..." In the old days the king from these parts used to be able to turn trolls into stone. Once when Olav the Pious came riding on his horse along a steep slope leading to a narrow valley, a troll hag came flying out of the mountain and shouted at him: - Tell me, man with the beard so red and stiff: Why do you ride so close to my cliff? But Olav was not so easily frightened so he shouted back at her: - Stand as stone in that same spot - And harm anyone more you shall not.
And so it was. You can still see the petrified troll hag standing there in the mountain.
From the book "The little Troll"
"....Some say we will crumble and turn to stone if the sun shines on us. Others say that we will melt and turn into nothing". "He remembers the big pile of rocks down the mountains side. That's all that is left of our forefathers, says Mama each time they passes it...."
From the book "Troll" Th. Kittelsen
".... Now the first sunbeam breaks forth above the dark outline of the mountains. He gritted his teeth in powerless rage and bit his evil tongues until the blood ran. His horny fingers tightened, his muscles and tendons stiffened like dawn bows. Then the sun rose. He reeled, stumbled over, while the humble mountain flower in the crevice raised its cup to greet the day, brimming with a gleaming silvery dewdrop.