Coridite

Coridite is a powerful crystal containing energy. It was used to forge He-Man's baldric.

Filmation
The Coridite is a crystal highly desired by Skeletor. It was mined by the Widgets, and Evil-Lyn was dispatched to steal it from them.

He-Man and the Masters of the Universe (2002)
The Coridite is found by Mer-Man in the Sea of Rakash and used to power the device built by Tri-Klops to crack the Mystic Wall which trapped him in the Dark Hemisphere of Eternia.

He-Man and the Masters of the Universe (classic cartoon)

 * Evil-Lyn's Plot
 * Jacob and the Widgets
 * The Gambler

He-Man and the Masters of the Universe (2002)

 * 1. The Beginning Part 1
 * 6. The Deep End