Runestones

A Runestone, or, in the plural form, Runestones is the group of special stones that give the Elemental Princesses of Etheria their powers. They also can form magical connections to First Ones tech, such as the Sword of Protection. When a person or piece of tech forms a connection with a Runestone, it makes that person or tech an elemental.
There are currently seven known runestones on Etheria: The Moonstone, The Heart-Blossom, The Pearl, The Fractal Flake, the Emberstone, The Black Garnet, and the Halfmoon runestone.

Significance

Runestones are the sources of the Elemental Princesses' powers, which are magical and native to Etheria. They help, along with Etheria's Moons, to regulate the weather and magic on the planet. The magic of a runestone is more powerful than all other magic on Etheria, except perhaps the moons of Etheria themselves.