The locket Horcrux was stolen by R.A.B - who is later revealed to be Sirus Black's brother, Regulus who deserted Lord Voldemort and died while stealing the locket. Instead, Kreacher the house elf was tasked with destroying the locket but a house elves magic is not one of the few things able to destroy a Horcrux. Instead, it was left in a cabinet in the Black house. That is until the Weasley's began tidying the house and threw it out.
Kreacher saved the locket, only for Mundungus Fletcher to steal it from him. In turn, Dolores Umbridge took the locket from him in exchange for not imprisoning him. Harry, Ron and Hermione later steal it back from her.
snape. his mothers maiden name was prince and he is halfblood. hence the halfblood prince.
yes
The fake locket Dumbledore died to obtain in Harry Potter & The Half-Blood Prince.
Yes, the horcrux inside of Harry Potter
he iin the entrance courtyard, ouside the entrance hall
The Horcrux which is Slytherin's locket that turns out to be a fake.
No, only the Horcrux inside him was.
No, but the diary Horcrux, was destroyed.
The diary
The Ring
yes
Harry Potter and the Half-Blood Prince is set in Hogwarts. The only time Harry leaves Hogwarts is to go to Hogsmeade, and to the cave where he and Dumbledore went to find the horcrux.