So, Medusa was going out with Poseidon (God of the Sea) and Pioseidon, being one of the Big three, thought he was well head, and so he took Medusa on a date in one of Athena's temples. This was totally disrespectful in those days, and so Athena was not happy. So, she turned Medusa (and her sisters too, for good measure) into horrible creatures with snakes for hair and ugly faces, tails too apparently. Now, this is the foundation and fact (or what's written down in the History books, anyway) of my answer. For the true answer, I'm guessing that Athena gave them the power to turn anyone who made eye-contact into stone as a curse, so nobody could ever choose them again, even if they were looking through the horrible looks. Because they'd be statues.
Athena caught Poseidon raping one of her followers, Medusa, in her temple. Interestingly, Medusa was punished, not Poseidon. Athena turned Medusa and her sisters into Gorgons.
Turning people into stone
The Three Gorgons were the creatures that could turn people to stone.
Medusa was one of the three "gorgons" their job was to turn people into stone.
They were turned into hideous creatures who have snake for hair and can turn people into stone with their gaze.
She is able to turn people to stone and is beautiful
Medusa, one of three gorgons. She could turn people to stone by making eye contact with them.
Medusa was a Gorgon. There were three Gorgons originally. Medusa had snakes for hair and as all Gorgons could turn men to stone.
In mythology, looking a Gorgon in the eyes turns the viewer into stone. Gorgons, like Medusa, have the power to turn anyone who gazes into their eyes into solid stone.
Their names were Stheno, Medusa, and Euryale. And as a group they were the Gorgons.
In Greek mythology, Medusa and the Gorgons were punished by Athena for desecrating her temple by engaging in a romantic encounter with Poseidon. Athena transformed Medusa and her sisters into hideous creatures with snakes for hair and the power to turn anyone who gazed upon them into stone as a form of retribution for their actions. This punishment served as a warning to others about the consequences of disrespecting the gods and their sacred spaces in Greek mythology.
There were three gorgons. There head looks weird and their hair is made of snakes. If you look at them you will turn to stone. The most powerful gorgon was Medusa.