Tourmaline (dravite) from the Simanjiro District, Tanzania
- June 1, 2017
- Cara Williams; John Bear Williams; Brendan M. Laurs; Alexander U. Falster; William B. "Skip" Simmons
- The Journal of Gemmology
Lace opal from Utah
- January 1, 2016
- Cara Williams; Alexander U Falster; William B Simmons; John Bear Williams
- The Journal of Gemmology