I am trying to locate a children's novel that I read in the late 1980s. I thought the title was something like Down the Mountain, but I haven't found any evidence of the book online. (Things are not helped by there being a significant number of of other children's books that have that as part of their name.) I don't remember it as a particularly good book, but it had one very evocative scene.
The novel deals with a group of children in the present day, who become involved in a quest to visit a magic spring atop a small-ish mountain outside the town where they are staying. Sometimes it's just a spring, but when they finally make it there, they find the spring located inside a castle that exists outside of time.
Before they head up the mountain, they meet a woman who was been the spring and has been trying to get back ever since. She has a rock she took from the fountain, which sometimes gives here clairvoyant powers. She also got a vein of gold out of the rock, which she had made into the frame for a set of glasses.
At some point, somebody who understands the spring's magic explains: "The water widens perception; the gold deepens it; and the rock has communicative powers." It's the power of the gold that really made an impression on me. When the kids look through the glasses with the golden frame, they can see people's auras. Of two nuns walking by, one has a holy golden glow; the other is surrounded by black crucifixes with writing figures. A baby in a carriage is blowing pink bubbles, but her mother is emitting a gray cloud of fog, which seeps into the bubbles and weighs them down.
I'd like to find the book again, just for that one vivid scene. However, I have no idea who the author was or how old the book was when I read it. I might or might not have the title correct, but if I recall correctly, I haven't located any evidence of the book on the Web.