(Spoilers TSR) Is Callandor ever mentioned before Book 3?

I'm about halfway through "The Shadow Rising" and it seems Callandor plays a crucial part for the rest of the series. However, I don't remember anyone ever mentioning it before, "The Dragon Reborn". You would think Moiraine would mention it at least once. Did Robert Jordan add it in later?

On that same note, it strikes me as odd that "The Great Hunt" focuses so heavily on the Horn of Valere, yet the horn is barely mentioned in book 3 and what I've read in book 4 so far. Does RJ like to jump around to different magical items throughout the series?

I'm not complaining...it's my first read and I'm loving The Shadow Rising. It's just an interesting thing I've noticed.