The Ata'mal crystal was an artifact of naaru origin bestowed to the eredar of Argus long before Velen's time. It was shattered into seven shards during the flight of the draenei, which have become lost over the last decades. The fragments are seen as both symbols of holy Light by the draenei and as potential weapons of immense power, notably by the Burning Legion and the Illidari.
The shards are in the colors of light as seen when refracted through a prism - red, orange, yellow, green, blue, indigo and violet. They are named Heart of Fury (red), Brilliant Star (yellow), Leafshadow (green), Spirit's Song (violet), Eye of the Storm (blue), Fortune's Smile, and Shield of the Naaru.
The Ata'mal crystal was a sacred artifact of the eredar, accessible only by their three leaders - Archimonde, Kil'jaeden and Velen. When the Dark Titan, Sargeras, came to Argus and offered the eredar to join his cause in exchange for unlimited knowledge and power, Archimonde and Kil'jaeden readily agreed, but Velen - who possessed the gift of Sight that the others lacked - saw the truth behind Sargeras' offer, and how he intended to lay waste to the known universe.
Praying for guidance, Velen's pleas were answered by the naaru known as K'ure. K'ure instructed Velen to take the Ata'mal crystal and rally anyone willing to listen to him, and travel to Argus' tallest mountain on the longest day of the year. There, Velen's prayers would be answered. As Velen and his followers awaited a sign from the naaru, Archimonde and Kil'jaeden had caught wind of Velen's plan and unleashed the man'ari upon them. Raising the crystal into the air in desperation, Velen watched as the crystal was struck by a beam of light and suddenly shattered. The crystal created a barrier of light that prevented the man'ari from reaching them. At that moment, the gigantic dimensional ship known as the Genedar appeared, providing Velen and his followers their escape from Argus.
- When Velen was captured and released by the Frostwolf chieftain Durotan, the Heart of Fury and the Brilliant Star were taken from him and utilized against the draenei. The Star's current whereabouts are unknown.
- The Heart of Fury was passed amongst the orc clans at each new moon, even coming to Durotan's hands for the orcs' attack on Telmor. At one point it ended in possession of the Shadowmoon fel orcs at the Ata'mal Terrace in Shadowmoon Valley, its presence clouded with dark magic to keep it from the Sha'tar. Akama, leader of the Ashtongue Deathsworn who served Illidan, sent adventurers on a quest to retrieve it. Akama then placed it into the , and instructed the adventurer to take it to the naaru A'dal in Shattrath City for safety. When the Sha'tar forces finally assaulted the Black Temple, the naaru Xi'ri returned the Medallion to the adventurer, allowing them to enter the Black Temple.
- Spirit's Song was last held by Velen, then lost in Outland. It would later be found in the hands of a dreadlord named Culuthas in Netherstorm, who believed himself above the Burning Legion with the crystal in his possession. Nexus-Prince Haramad, leader of the Consortium, sent a party to triangulate its location, and reclaim it for Kael'thas and the Sunfury, but inspired by the selflessness displayed by the adventurers in bringing it to him, Haramad attuned his personal teleporter to Shattrath City, where it was delivered to the naaru A'dal instead.
- was held by Restalaan, long-time friend of Velen and captain of the guard in the city of Telmor in Terokkar Forest. It was used to cloak the entire city, protecting it from the ogres and their gronn masters. Durotan and Orgrim learned of its existence during a childhood trip to the city. But one day, Durotan - who remembered the necessary words to lower the shielding illusion - revealed Telmor to his forces, and the orcs proceeded to sack the city. Once in the Horde's possession, it was used against the draenei to hide the orcs' assault on Shattrath City until the last possible second. Its current location is unknown.
- The Eye of the Storm was originally planned to be located by Kanrethad and Jubeka in the Black Temple and then delivered to Wrathion in Pandaria by the player character. These plans never made it live, and so the Eye of the Storm has yet to appear in-game.
The other crystals' locations and purposes are unknown, but they presumably are still in the possession of Velen and the draenei.
- Illidan's demons and their Broken slaves were trying to dig up an Ata'mal crystal shard in the Ruins of Sha'naar in Hellfire Peninsula, but it was in all likelihood not even there according to Naladu.
- One of the alternate portraits for Velen in Hearthstones Mercenaries game mode shows him wielding all seven Ata'mal crystals during the battle in the Tomb of Sargeras. In canon, none of the crystals are known to have been used in the battle.