Sometimes when you travel, you pick up souvenirs. You might buy a post card and you’re almost certain to take a few (or a lot of) photographs, which for most of us really help to keep memories alive. We can look at the photographs and remember what it was like wherever we happened to have been. Or we might buy a small object in a store or at a market to remember the trip by. In our family, we sometimes pick up stones. Sometimes they are selected because they’re a particularly pretty color or have a nice pattern on them. Other times, it’s their shape or the smoothness of the surface. Some here—the green one at the top and the bluish green one on the right—are from the Nevada ghost town where my grandfather was born, 135 years ago.