Welcome to the Board, #1.
I'm sorry to hear about your father and understand your need to know what the rock "treasures" are that he collected.
I hope we can be of some help.
But I have to tell you, good pictures of the rock cobble, but I don't think you could find a more complicated rock to begin with.
Look at all the different things going on in that rock! Probably 10-15 different minerals.
It looks like an igneous breccia. You can look that up to start with but then you just start trying to identify each
individual piece in the mix. What are the white spots? the green spots? and so on.
It would be hard to tell when and how it was formed without know "where" it came from.
If you know where it came fom then it is much easier to find out what it is by looking up the USGS information on the area.
And locals may have a real easy name for it already, " Oh yeah, that's that Black Mixed-Up Granite stuff."
And maybe someone will recognize the material and chime in.
Same goes for your other pics of the large rocks.
Very cool looking rocks and it will be very interesting to figure out what they are made of and how they were formed.
To do that we need to know where they are. Northern California?
Any information about the source of these rocks is pretty critical.
Thanks for the pics,
Joe