Board Thread:Warhammer 40k General Discussion/@comment-25618639-20141125142918/@comment-24944355-20141126045004

Given how chaos want to deface anything connected to the Emperor & also how jealous Horus was of him it's quite possible that the traitors went out of their way to wreck or corrupt it. If so I don't think it's fate has been revealed in the books as yet but it might be included in a yet to be released novel. The fact I have yet to hear any mention of it's existence in the future 40k time period does not bode well though.