Just something I thought of while I was in the shower.
Three of the first known horocruxes (cup, locket, ring) were made after Tom was out of school. But what if he made one while he was still in school? If you think about the four houses and what their valued possessions or "trophies" might be you might be able to figure out one of the last remaining horocruxes.
1. Gryffindor = Godric’s sword, which represents bravery, valor, chivalry.
2. Hufflepuff = Helga’s cup, which would represent either a Holy Grail of some sort or just a goblet that is used to indicate drinking and good times.
3. Slytherin = Salazar’s locket, an enclosure of Salazar’s heart’s desires. The center of the heart’s deepest desires is referred to as the emotional ego. The house of Slytherin’s element is water, which is the astral or emotional plane.
4. Ravenclaw = with this one, the answer is almost too obvious. What was Rowena’s main goal in life other founding a school? To obtain as much knowledge as possible. How does one obtain information? By reading books.
A book would be the most likely candidate, as it is an object she was prize above all. Her second love would be for the school she helped found, Hogwarts. Assuming J.K. Rowling has already mentioned the said book before, as she most often foreshadows or hints at things like she has done all throughout the series, one must think of a book that would intertwine both of Rowena’s two most cherished things. The only book that comes to mind of course is Hogwarts, A History.
I know, I know, why would Voldemort make a horocrux out of something and then leave it out for everyone to have access to? But if you think about it, keeping it at Hogwarts is actually rather clever. The book is perfectly safe there, and no one other than Hermione The Nerd is actually going to read it, open it, touch it, etc., as it is probably frightfully dull and boring. However, Voldemort failed to realize that he was not the only one who knew about horocruxes so in the end this is probably going to come around and bite him in the ass.
Hogwarts, A History is mentioned multiple times throughout the series, and I would like to think this had been on purpose and not just pointless random text typed up to make the books longer. On a side not, I thought I might also mention this bit of information concerning the matter in an interview:
MA: Will Harry and Ron ever read “Hogwarts, a History”?
JKR: Never. [Laughter.] It’s a gift to me, because all my exposition can be dressed up as, “When are you going to read it?” So Hermione fills in the reader as well, so I could never let them read it. - from "The Leaky Cauldron and Mugglenet interview Joanne Kathleen Rowling: Part Three," discussed in 2005.
This would explain why neither of the boys ever read the book in the first place because: a) it’s boring and b) once they finally figure out it was a horocrux, they were busy destroying it to actually have time to read it.
Anyone else's thoughts on the matter?