> There are a few species you can sometimes find in washes when they get buried during massive floods, but other than that most museum quality specimens are impossible to find for rockhounds.

Well, that's kinda how it has to be, right? If art museums displayed the artwork anyone can paint, they wouldn't be interesting to most people. Most museums are about displaying the stuff you otherwise wouldn't be able to find, buy, or make. It's still fun to learn to paint, even if you're no Rembrandt.

To be fair, there are some museums that go for depth instead of scarcity and I personally find them more interesting. The Computer History Museum does this pretty well. They have some truly unique items, but also plenty of stuff you can buy on eBay, just presented and explained well.