Thanks for the help with the pictures, Dave!
And I agree with Fuss, it's not a geode, it's an impressively large crystal!
Nice find. Any chance of going back and trying to find the vein or pocket it came from? I'm sure that's what the geologists would like to do. Besides for the incredible size of that crystal, it is a real good sign of 'other' geologic activity. Kind of a red flag marking a hot spot. Often times there are other interesting minerals in and around crystals. Like the "Barrerite" they talk about in the link below.
I'm glad to hear you are planning to keep it.
As far as value goes, good question.
Did a brief google search and came up with this site for some info,
and there's quite a few others.
http://www.stoneartsofalaska.com/index.htmDidn't find anything about Alaskas' Largest Quartz Crystal. Checking with the State offices would be the quickest way to track that down. It is big, but as I've always said, the big ones have more room for ugly. The damage on the crystal could be from 'contact growth', which isn't as bad as a ding. And yes, you can clean it up a lot with Iron Out or Oxalic acid, but I wouldn't be in any hurry to do that. Some of that surface mineral oxide accumulation could be just as interesting as the crystal.
I haven't read much about the geology of Alaska. Gold, gold, gold. It will be interesting to look up a little about the Quartz Crystals of Alaska.
Keep us posted!