The Elfstone is the stone from which Aragorn took his name. It was given to him by Galadriel, shortly after the loss of Gandalf in Moria.

The stone was set in a silver brooch shaped as an eagle with outstretched wings,and the gem was of the clear green of sunlight coming through spring leaves.

Galadriel told Aragorn that she had given the stone to her daughter, Celebrian, and that Celebrian had given it to Arwen. She then said that now it was to go to Aragorn as a token of hope. Hope - that Sauron would fall, that Aragorn would become High King, and that he could then marry Arwen. While Aragorn's birth name Estel, already meant hope, at that time, he took on the name of Elessar, the elfstone of the house of Elendil.

Tolkien gave several versions of the origin of the Elfstone. In the earliest version (Unfinished Tales), the Elessar was made by the greatest jewel-smith of the Noldor, Enerdhil. Later, Tolkien dropped Enerdhil and used Celebrimbor instead. Another early version had two Elessar stones. Enerdhil made the first Elessar, but it was lost. Celebrimbor then made another, more subtle and clear than the original. This one was lesser only because by that time Melkor had dimmed the light of the sun.

Celebrimbor (in the final version) then gave the stone to Idril. She was wearing it when Gondolin was attacked and destroyed. Before sailing away in the escape, she passed the brooch to her son, Eärendil. He then wore it at sea, including on his journey to ask for aid from the Valar. The stone later came to the hand of Olórin the Maiar.

During Gandalf's travels, he came to Galadriel, saying that he had brought her the Elfstone from Yavanna, with the instructions to:

"Use it as you may, and for a while you shall make the land of your dwelling the fairest place in Middle-earth. But it is not for you to possess. You shall hand it on when the time comes. For before you grow weary, and at last forsake Middle-earth one shall come who is to receive it, and his name shall be that of the stone; Elessar he shall be called."

It was said that the stone also held unusual properties. Looking through it, the viewer could see an injured or aged thing or person as in its original state of beauty and youth. Also, the wearer's hands could bring healing from injury. In a later version, this power extends over the land as well. This idea of healing may have been involved when it was said that the hands of the king would be the hands of a healer - the power may have been augmented by or derived from the Elfstone.