Health Effects of Stones: (positive and negative); Jade is said to be positive;
Worldcat Subject Headings:
Precious Stones >> 5,286, all formats; >> 4,221, books; >> 221, journals and periodicals;
Stones -- folklore >> 284, all formats;
Specific Stones:
Gray Pebbles: (fictional, ruthenium, said to be a catalyst in artificial photosynthesis, and has strange, self-heating properties; found in far North of Canada, Cussler, Artic Drift, pp. 186-187, 256+
Green stones: (reported by early explorers in South America as being kept by local Indian tribes;)
Jade: said to have a positive health effect;
Petoskey Stones: I think it was Mr. Ed Pagel who told me around 1965 that there were many to be found on the east side of Burt Lake. I went there and found Buckets of them, both on shore and just off shore.
Swedish Stone: (Used by to somehow capture and convert cosmic energy to electricity)