Unusual rock found while prospecting in wisconsin creek

[mattfink]

we find these rocks all the time and I was wondering if anyone could id them.


and then we have it with light shinning through it.

 

Amazon Forum Fav 👍

A Handbook of Civil War Bullets and Cartridges - Grab it through Amazon!

[Jason in Enid]

It's lava.

 

[stonecutter1]

Matt, It looks like there are some veins of microcrystaline quartz lining some of the rock. Can't tell real well from your pic. I grew up in Minnesota in the suburbs north of Mpls. I used to crawl around the gravel pits looking for agates. I found similar looking rocks to the one you found. I read some of your posts on glacial gold deposits. Very interesting! I never did any gold panning up there. My dad still lives in MN. He is near Becker. I get up there once a year or so. We work some areas Missouri that has glacial gold like up there in Mn.

 

[Fullpan]

It's lava.

Yes, lava with chalcedony or calcite? (the white material), pretty rock but pretty common.