Do you want your own private Idaho?
I was in the garden today and picked up a rock that looks like Idaho! It's not very big, about 1.5 inches on the tall side, 1.25 inches across the base, and very flat.
If anyone in the US feels they need a free Idaho rock from Missouri, PM me, and I'll mail you a rock, for no good reason, except it's too neat to toss back in the garden, and I don't need an Idaho!