Indiana jones kingdom of the crystal skull?

it is actually both - the aliens have skelatons made of crystal. if you listen in the movie indy says it is quartz and not formed with any tools - the quartz is the crystal - and they are from the aliens. Like Indy also said, they wrapped the heads of the village children to be like their God - so the regular skulls were the villagers. When the lady turns to dust, its because she could not handle all the knowledge they were giving her -she said she wanted to know everything, but she couldn't handle it - besides that, the bad guys always die at the end of the Indiana Jones Movie.