That makes finding places to explore together much easier with geology in common.
I hope that you'll get to do your trip out to Canada, it makes sense to go somewhere that you haven't previously explored.
I would assume that things like Fire Agates would be like opals and become more scarce as time goes on, but I don't know that much about the formations out there.
Isn't Rio Grande also the name of a jewellery equipment supplier in the US?
They are all cryptocrystalline silica (sand). However, they are so small grains that even is basic crystal structure is visible with microscope. Typically very fine layers of Geothite and Laterite (both iron oxide) and interlayered with Agate to give that unique red color that comes out when polished. During the Tertiary, post Oligocene, 28 Ma ago to the last Ice age, there have been a lot of volanic eruption is the west and southern US. Fire Agates are associated with that.
Rio Grade is a river in the sourthen US, that flows through the rift of the that same name. Its a rather common name in the US.
https://en.wikipedia.org/wiki/Rio_Grande_rift
https://geoinfo.nmt.edu/publications/periodicals/litegeology/33/lg_v33.pdf
These will help you get oriented if you are interested.
Ah ok, that makes sense as to why some of them have the bubble like looks, I didn't know much about how they are formed and the connection to volcanoes, I appreciate the insight.
I'll go take a read on the links you shared, thank you.