A key weapon in Harry Potter is the enchanted Sword of Gryffindor. As big of a part as it played though, there are a few facts that remain obscure.
A key weapon in Harry Potter is the enchanted Sword of Gryffindor, first coming into existence over a millennium before the events of the main timeline. It is said to share an intrinsic link with anyone belonging to House Gryffindor, considering the person it is named after. Then again, it's probably a sense of intrinsic courage that forms this bond, and not the mere act of sorting students.
The Sword of Gryffindor is first used to kill Salazar Slytherin's Basilisk and later appears throughout the story in different locations. For example, it is employed in the destruction of the locket Horcrux, and later by Neville Longbottom to decapitate Nagini. There are a few facts about this item that remain obscure knowledge, though.
As expected from their general predilection towards treasure and jewels, it is the Goblin community who casts the sword over a millennium ago, around the time Hogwarts was founded.
Being extremely talented blacksmiths (as well as having sufficient intrinsic magic), they manage to make an unparalleled weapon for Godric Gryffindor himself. The skill of the chief architect, Ragnuk I, is basically the reason why this sword vibrates with incredible power.
Unfortunately, as Goblins are beset by their love for wealth, it often turns to greed when the object in question happens to be of inestimable value. As such, Ragnuk desired the sword of Gryffindor to the point that he hires goons to "retrieve" the object back from Godric Gryffindor, that too after their deal had been struck and exchanged.
The wizard proves far too adept to lose to a bunch of skulking Goblins, but does not murder them; instead, he tells them to warn Ragnuk of the consequences of attempting theft for a second time.
In The Lord of the Rings prequel, The Silmarillion, there is a tale of the most exquisite necklace to ever exist in Arda. Forged by the Dwarves under the instructions of King Thingol of the Sindarin Elves, it becomes almost incomprehensible in its majesty when the Silmaril of Luthien is embedded within it.
The Dwarves are instantly covetous of their own creation and have the audacity to ask Thingol for the Nauglamír itself as payment (a business paradox that failed to work in their favor at the end.)
The most famous sword in British lore (or even in the Anglosphere) is the ancient Excalibur, the prized weapon that once belonged to King Arthur. In addition to the similar timeline — both obviously fictional — there are a few matching narrative elements.
For instance, the sword of Gryffindor is extracted from the bottom of a small pond by Harry, with Ron's help, and Excalibur is obtained through the beneficence of the Lady of the Lake, who also takes her gift back after its usefulness has been completed.
The sword of Gryffindor is composed of the purest form of silver, known as Goblins' Silver, which is said to be immune to dust, almost unbreakable, rather expensive. For instance, armor made of this material costs more than five hundred Galleons (apparently several thousand dollars in Muggle money.)
Rubies are also present in the hilt of the weapon, being the precious stones that are most identified with Godric Gryffindor. Then again, why didn't he make it from gold, considering that silver is a Slytherin-based element? Too heavy?
One of the unique properties of Goblins' Silver is that it can repel anything it wants, from blood to grime to water, but whatever it does absorb only serves to make it more powerful. This is how Ron destroys the locket and Neville is able to vanquish Nagini, a feat that wouldn't have been achieved before its first use by Harry in the Chamber of Secrets.
When the hero destroys the Basilisk of Slytherin, the venom pouring out of its mouth supposedly coats the sword of Gryffindor, allowing the weapon to act as an extension of one of the beast's fangs.
Owning this object is not the most appropriate term — the sword allows its wielders to employ it if and when necessary, sort of like Sauron's One Ring (except not evil.)
In any case, the first character to have the sword of Gryffindor in their position is Ragnuk I, followed by Gryffindor, Harry, Dumbledore, Snape, Ron, one of the Snatchers who took the Golden Trio to Malfoy Manor, Griphook the Goblin, and, finally, Neville Longbottom. Its current whereabouts aren't defined, but it's likely stored in the Headmistress' office.
Dumbledore, knowing exactly what Harry would have to face, bequeaths the sword of Gryffindor to him, which he only learns of long after the Headmaster's death.
Unfortunately, the then Minister for Magic, Scrimgeour, pompously announces that the item belongs to Hogwarts, and thereby cannot be inherited by anyone. This is just one example of the gall exhibited by the Ministry, whose habit of poking their noses in school affairs has been in vogue for the longest time.
The sword and the Sorting Hat are inextricably entwined with each other throughout the course of history, mostly because both of them were originally Godric Gryffindor's.
Therefore, in the event that a "true Gryffindor" requires its services, it automatically appears to them from inside the Sorting Hat. Harry gets it in The Chamber of Secrets, while Neville procures it when Voldemort magically superglues the hat to his head right before the Battle of Hogwarts.
Like many of the objects in Hogwarts, the Sword of Gryffindor displays at least some degree of sentience, possibly even sapience. Excluding the fact that it's transportation is covered by the Sorting Hat, how does it decide what a "true Gryffindor" is in the first place?
Can anyone courageous enough be given the honor to wield the sword? Or does one compulsorily have to be sorted into the House before getting access? The previous one seems more likely since the concept of school Houses is not a rigid definition anyway.
