In need of help identifying a large rock

[DWood]

While wading a river in the cascade range I found what I thought was a large piece or stump of petrified wood but after digging it out of an undercut back, rolling it across the river and getting a buddy to help pack it to my pickup and bring it home I’m doubting it is but I really want to know what it is. Weighs about 350# and 3’ in diameter, I see lots of quartz I believe so I cut a chunk out of it of which I will post a photo.

 

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[IAMZIM]

It looks a lot like chert to me.

 

[hvacker]

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[Moesia]

Looks like hydrothermally altered, weathered rock. The rock looks completely leached of sulfides once present. If that is indeed quartz (try to scratch different parts with an iron nail, press hard), you should try to break the rock open and look for any remaining sulfide minerals. Look carefully for gold also, it should be native and very small if there is any visible gold at all. Don't confuse it with pyrite if there is any. In the great majority of cases, any gold that might appear in these kind of rocks is not visible to the naked eye and you have to assay the rock to know.

I don't know what you are interested in, but I hope that helps.