Untersuchungen an Titanit, einem für Sri Lanka neuen Edelstein
Untersuchungen an Titanit, einem für Sri Lanka neuen Edelstein. Published in Zeitschrift der Deutschen Gemmologischen Gesellschaft, 1982. Author(s): H.A. Haenni
Ferroaxinite – another new gem from Sri Lanka
Ferroaxinite – another new gem from Sri Lanka. Published in Journal of Gemmology, 1982. Author(s): H.A. Haenni, M. Gunawardene
Blue colour-changing kyanite from East Africa
Blue colour-changing kyanite from East Africa. Published in Journal of Gemmology, 1982. Author(s): G. Bosshart, E. Frank, H.A. Haenni, N. Barot
First occurence of gem sphene in Sri Lanka
First occurence of gem sphene in Sri Lanka. Published in Journal of Gemmology, 1981. Author(s): M. Gunawardene, H.A. Haenni