Need Help Identifying This Huge Rock

[Daughter of a rock hound]

This rock is pink and white, and weighs at least 100 pounds. I think my father found it 70 years ago in the Napa Valley River, but I’m not positive. Please help me identify it. Thank you so much!

 

[Plug N Play]

From an area with known volcanic activity, including Glass Mt. and St. Helena obsidian.
I'm gonna lean away from the chert/jasper possibility and go with the big favorite,
A big hunk of Napa Canyon Rhyolite ...

 

[Geochem]

Plug made an exact identification for you.

 

[Daughter of a rock hound]

Thank you so much! haha, my friend almost had me convinced it was corundum... sigh You can’t see it in these photos, but in the nooks and cranny’s are green and a couple blue crystals... also some white, red, pink and yellow ones. Is this a host rock for any gems?

 

[Steve1236]

I'm not thinking that's ryholite, texture doesn't seem right, it's not corundum, I'm thinking quartz/chalcedony/jasper, one of those but they are all quartz in the end.

 

[A2coins]

Thats pretty cool that would be a beast to haul that anywhere to be looked at there is a rock and gem forum on here also might have more opinions.

 

[A2coins]

Welcometo tnet from Mi

 

[xaos]

Knights Templar