Prologue

"Alex" Ashley gasped. It was beautiful. The ring, it was beautiful. A moonstone. His was a sunstone. She fell in love with the gems her and her husband would call their son and daughter. They were never able to find out what they were but she raised them like humans, glad most people ignored their bizarre appearances.

One summer, it was secretly decided they needed to find their own kind at some point. They sent Dipper and Mabel to the likeliest place they'd find others like them.
Gravity Falls.