TIME TO EXPLAIN MY USERNAME
When they are being chased by nazgul, he is waffling over using the bridge openly, in cause it is a trap, and he decides they’re going to trust it because he finds a pretty rock. Which he calls an elf-stone, like the name he’ll eventually take, but obviously this is not THE elf-stone.
And Glorfindel had cleared that bridge earlier. And he was like “hmmm what symbol can I leave that Estel would definitely notice, and make known to him the way I’d safe? I know! A pretty rock! Estel loves cool rocks.”
And literally this was not an agreed upon symbol, Aragorn just goes “An Elf stone! These are good luck!”
And I am now convinced that little Estel growing up in Rivendell, would bring Elrond or his mom or any elf who he wanted to make friends with a rock he found that he thought was neat.
And of course, all of the elves are like “oh no, it’s cute!” Because here is this solemn little boy who wants to share the things he likes with them, and Elf children are rare at this point on middle earth, so all of these ancient elves are like. These garden stones. Are treasures.
And Elrond encourages his hobby, and helps teach him about types of rock and geology, because he is absolutely the Learning is Fun! Dad, but also he’s the heir to the Kings of the Noldor on middle earth, married to the niece of Felegund, who lived among the Gwaith i Mirdain for a while. Knowing about all types of rocks is probably, like, the Noldor equivalent of learning about all sorts of animals in kindergarten.
And because he absolutely unknowingly has the entire valley wrapped around his finger, elves start hiding interesting rocks around Rivendell. And uncut semi precious stones.
And Estel brings them to Elrond to help him look up in a book, and the Lord of Rivendell has to look at a young boy with a straight face and say, yes, it’s possible for raw emeralds to show up on the banks of the Bruinen, elves live here, lots of special things pop up around elves.
And so he calls them elf-stones, and is very happy with his little collection, and he shows all his friends who are all very impressed, some of them are rare and some are just odd shapes, or an interesting pattern, and not all of them got left around by elves in the longest Easter egg hunt of all time.
So Estel grows up, and becomes chieftain of the Dunedain, and has to leave his collection behind because he can hardly carry around a bunch of rocks as a Ranger, but sometimes he’ll bring one back when he visits, because collecting rocks and sharing them with his friends is a very happy memory for him, though what he finds is rarely as nice as the ones he’d find in Rivendell.
And all this to say, Glorfindel, who was absolutely one of the elves who hid rocks for Aragorn, is thinking of what to leave as a sign that won’t be too obvious, but he will definitely notice… and well, Glorfindel is also a Noldo, and he has a green stone in his pocket that DEFINITELY doesn’t belong among the stones on the bank here, but Aragorn will be sure to spot it and know a friend was near.
I have not decided if Aragorn legit still believes cool rocks pop up around elves, or is looking for any sign and it’s the only bright happy thing in a desperate world, but he totally got the message either way.
And that’s my Aragorn’s rock collection headcanon.
Arwen loves his rock collection btw. The first present he gives her when he has nothing and falls for her in Lothlorien is the small stone he’d carried in his pocket for miles.
He tells her how he started picking them up and giving them away as a child, and how now he only lets himself carry one he finds on his journeys. And so if he finds another he likes he has to choose between them. But because of that each stone is both a memory of his journey, and a reminder of his homecoming.
And she looks at this smooth white river stone- she is also a Noldo, this is a completely valueless piece of impure sedimentary quartz and calcium carbonate- in the palm of her hand. It came out of the pocket of this greasy man who called her her great-great grandmother’s name completely unironically, and looks into his hopeful grey eyes and just thinks “goddamnit I’m going to marry this poetic idiot and be so fucking happy.”
She gives him the most important stone of his collection, THE elf-stone, (at least she tells her grandmother she wants him to have it), and it’s slightly important to his fate or something, and he literally names himself after it so it’s kind of a big deal but he still insists completely straight faced that the one he gave her was better.