Aayla Secura bestowing the Heart of Fire upon Xiaan Amersu. Originating from the planet Kiffu, a Heart of Fire was a radiant gem, typically red in color. Certain, more valuable Hearts of Fire exhibited a blue hue, making them more precious than the red ones. On Kiffu, tradition dictated that these stones be gifted to loved ones as a sign of affection. Legend held that the stone contained a fragment of the spirits of both the giver and the recipient. Jedi Master Quinlan Vos presented a Heart of Fire to his Padawan Aayla Secura on the occasion of her thirteenth birthday. Later, when Aayla encountered Xiaan Amersu, she passed the stone on to her. After Quinlan suffered memory loss and returned to the Jedi Temple, Xiaan returned the Heart of Fire to Quinlan.
Boba Fett gifted a Heart of Fire pendant to his wife, the Kiffar bounty hunter Sintas Vel, who retained possession of it for numerous years, until her disappearance. In the year 40 ABY, Boba requested his granddaughter Mirta Gev, who possessed one-quarter Kiffar heritage, to attempt to decipher the stone's secrets using psychometry, hoping to uncover the circumstances surrounding Sintas' fate. Mirta responded that, due to her not being a full Kiffar, she lacked the capability to do so. Ultimately, Boba and Mirta located a former Jedi masquerading as a Kiffar to interpret Mirta's portion of the stone, which provided a clue that revealed Sintas was still alive, although trapped in carbonite.
Following the retrieval of the carbonite-encased Sintas Vel from the government of Phaeda by Boba and Mirta, they revived Sintas on Mandalore. Despite being blind and suffering from amnesia upon awakening, Sintas immediately inquired about her Heart of Fire pendant. Mirta then relinquished her half of the stone to Sintas, who commented that it felt altered. Subsequently, Boba acquired another, larger Heart of Fire for her, this one imbued with all of his memories from the time he had been separated from her. Boba offered her the stone shortly before their granddaughter's wedding; while she initially refused it, Boba insisted she keep it, should she ever desire to "catch up". Sintas then proceeded to read the stone after Mirta's marriage to Ghes Orade had taken place.