Heart of the Mountain
The Heart of the Mountain, also called the Arkenstone of Thrain, is the most prized treasure in the vast hoard of the dwarves beneath the Lonely Mountain. It is a great white gem, a globe with a thousand facets that shines like silver in firelight, like water in the sun, like snow under the stars, and like rain upon the Moon. The dwarves discovered it beneath the roots of the Mountain long ago, and it became the heirloom of the line of Durin, the symbol of the King under the Mountain. Its beauty and worth surpass all other gems and gold in the hoard, and it holds an almost magical enchantment over those who behold it, especially the dwarves of Thorin's company.
Discovery and the Dwarves' Desire
When Bilbo Baggins first enters the great treasure hall of the Lonely Mountain after Smaug has departed, he is drawn by a pale white glint that shines above him in the gloom. Climbing the great mound of treasure, he sees the Arkenstone glowing with its own inner light, tinged with a flickering sparkle of many colors reflected from his torch. The gem is large and heavy, and as Bilbo lifts it, he is overcome by its enchantment. He puts it in his deepest pocket, knowing that it is the Heart of the Mountain and that Thorin values it above a river of gold. Thorin, meanwhile, has been searching for the Arkenstone among the hoard, speaking of it as beyond price and naming it to himself alone, vowing to be avenged on anyone who finds it and withholds it.
The Arkenstone as a Pawn in the Siege
As the siege of the Mountain unfolds, with the Elvenking and Bard demanding a share of the treasure for the destruction of Lake-town and the slaying of Smaug, Bilbo sees the Arkenstone as a means to prevent war. He takes the gem from his bundle and, under cover of night, slips out of the dwarves' fortress and crosses to the camp of the besiegers. There he presents the Arkenstone to Bard and the Elvenking, offering it as a bargaining chip to secure peace. He tells them that Thorin values it above all else, and that it will aid them in their negotiations. The Elvenking, whose eyes are used to wonders, stands up in amazement, and Bard gazes at it in silence, as if a globe filled with moonlight hung before them.
Thorin's Rage and the Breaking of Trust
When the Arkenstone is presented to Thorin during a parley, he is stricken dumb with amazement and confusion, then filled with wrath. He denounces Bilbo as a traitor and a descendant of rats, and in his rage, he shakes the hobbit and threatens to throw him from the wall. The revelation of the Arkenstone in the hands of his enemies breaks the trust between Thorin and Bilbo, and Thorin agrees to give a fourteenth share of the hoard in silver and gold in exchange for the gem, but he declares that this shall be Bilbo's promised share, and that no friendship goes with him. The Arkenstone thus becomes the catalyst for the final confrontation, as Thorin, consumed by the dragon-sickness, refuses to yield any more treasure and prepares for war.
The Fate of the Arkenstone
After the Battle of Five Armies, in which Thorin is mortally wounded, the Arkenstone is laid upon his breast as he is buried deep beneath the Mountain. Bard, who had held the gem, places it on Thorin's tomb, saying, "There let it lie till the Mountain falls! May it bring good fortune to all his folk that dwell here after!" The Arkenstone thus returns to the earth, becoming a part of the Mountain's heart once more, a symbol of the dwarves' lost king and the enduring legacy of the line of Durin.
