Ruby & Sapphire: A Gemologist’s Guide by Richard W. Hughes with Wimon Manorotkul and E. Billie Hughes.
- CNN – How sapphires are changing Madagascar’s fortunes
- Sapphire mining and trading around Ilakaka, Madagascar by GIA
Ruby & Sapphire: A Gemologist’s Guide by Richard W. Hughes with Wimon Manorotkul and E. Billie Hughes.