Considering that Fiendfyre (apparently sentient demonic or elemental fire), Basilisk Venom, and Ancient Enchanted Objects were the only things that could destroy a horcrux...well, I think you did it a bit too easily in this chapter. If it was as easy as casting some over powered (maybe dark) spells to destroy a horcrux then there wouldn't be any point in making them at all. It probably would've been easier if he'd called for Dobby to retrieve a fang from the basilisk or the sword that killed the basilisk.
Even if he doesn't know if the sword will work.
Author's response
Something else that I was planning to reveal later but maybe should have explained at the time. You see actually it was the last spell that did it. It translates to "Wrath of Hecate" and I'd hate to spoil it too much but it is spell only witches can cast and is connected to my take on religion in the Potterverse. Specifically religion among the more ancient families. I was going to go into it in more detail when we get to Wedding plans for Tracey but I could try to fit it in if enough people think it would help comprehension. I don't want to spell everything out but I don't want to be too obscure either. hmmm, something to think about. Thanks for your comment.
I've also had people glad that I used something other than fiendfyre. I do think that the ancients of the Potterverse must have been able to destroy the things otherwise there would be a lot of people who came back. Especially Egyptian royalty. After all Voldy made a lot so he seemingly didn't think them too tough.
I should really be discussing this with a beta rather than rambling in a review reply but I don't have one.
P.S. When you get to later chapters you'll see another method of removal. I hope you like that one better as I took considerable pains getting it right.