A longtime friend was a goldsmith/jeweler.
Even playing golf in the mountains we would detour thru a creek or rockface just to see what was there.
He found stuff everywhere. Garage sales were great he could see real stuff in the middle of a table of costume jewelry then buy it for a song.
Before his death we had started cutting some opal out of the substrate. It is Aussie opal i got many years ago for a little work hauling stuff to a new building. I have about 50lbs with some nice exposed veins. One piece has a 4"X 4"X 5/8" thick slab on one side with more peeking out all over the boulder.
I have rocks in the yard from North Georgia and Montana. My wife likes rocks and i have to tote them home.
There is beauty in the natural world.