1. U.S. Geological Survey, MS964 Box 25046 Denver Federal Center, Denver, Colorado 80225, U.S.A.
2. † Special collection papers can be found online at http://www.minsocam.org/MSA/AmMin/special-collections.html.
3. U.S. Geological Survey, MS973 Box 25046 Denver Federal Center, Denver, Colorado 80225, U.S.A.
4. Planetary Science Institute, Lakewood, Colorado 80227, U.S.A.
5. 10414 Southwest 26th Street, Davie, Florida 33324, U.S.A.
6. Department of Astronomy, Mount Holyoke College, 206 Kendade, South Hadley, Massachusetts 01075, U.S.A.