The Earth pony, Unicorn, and Pegasus Crystals are featured in My Little Pony: A New Generation.
History[]
According to Discord, one day, a mysterious wicked unicorn pony came along and caused pandemonium by convincing some ponies into hating each other. Soon ponykind found themselves divided, which caused a terrible event to happen.
To make sure magic never pitted unicorns, pegasi, and earth ponies against one another, Twilight Sparkle gathered all the world's magic and placed it in three crystals. As long as these crystals were protected, and all ponykind lived in harmony, magic would be kept alive and well in Equestria.
Earth pony crystal[]
The earth pony crystal is clear, and shaped like a circle. It's supposed to represent the hooves of an earth pony, and the Element of Land.
Unicorn crystal[]
The unicorn crystal is purple, and shaped like a horn. It's supposed to represent the horn of a unicorn, and the Element of Sea.
Pegasus crystal[]
The pegasus crystal is light blue, and shaped like wings. It's supposed to represent the wings of a pegasus, and the Element of Air.
Together[]
The three crystals fit together, representing the friendship between all three pony kinds:
