1977 International Thematic Stamp Exhibition “Portucale 77” – Porto, Portugal – Gemstones. Full set details here.
Minerals represented: Beryl (emerald), and beryl (aquamarine).
1989 Precious Stones. Full set details here.
Mineral represented: Tourmaline.
1998 Brazilian Gemstones. More information here.
Minerals represented: Chrysoberyl (alexandrite), chrysoberyl (cat’s eye), and tourmaline (indicolite).
