Why did medusa turn people into stone?

Answer 1

In Greek mythology a Gorgon is a monstrous feminine creature whose appearance would turn anyone who laid eyes upon it to stone. Later there were three of them: Euryale ("far-roaming"), Sthenno ("forceful"), and Medusa ("ruler"), the only one of them who was mortal. They are the three daughters of Phorcys and Ceto.
The Gorgons are monstrous creatures covered with impenetrable scales, with hair of living snakes, hands made of brass, sharp fangs and a beard. They live in the ultimate west, near the ocean, and guard the entrance to the underworld.with such powers no one could defeat such creature all would turn into stone making the entrance of the underworld the largest statue museum. A wise man did not look straight but showed her a very well polished steel shield in wich medusa killed herself with her most powerfull weapon. She saw the reflection in the mirror like polished steel shield and became stone herself.

of course this is all mythology. why did they have that power? It was a good legend to spread and then place images of in shields of ancient greek soldiers for Psycological effect as well as in palace entrance or temple doors and coins.

Answer 2

She was cursed. She was one of Poseidon's women and Athena caught them in her palace. She cursed the girl and then she was called Medusa. She turned people to stone when they looked her in the eyes. Do you need any more?