Necklace at #12

[Jo]

No: HPFGUIDX 140048

I have been re-reading all the books and when I came to OotP, I 
noticed that the necklace with the medalion that no one could open was 
being put in the stack of items to discard when they were cleaning. 
There was no indication that Kreacher rescued it. (Page 116, US 
edition) Does anyone know where it went, since it has been mentioned 
frequently as a possible Horcrux. It appears to have been discarded 
with the trash.
Jo